According to medieval legends, around the year 800 Charlemagne and Pope Leo came into conflict with the city of Rome. The Pope was being attacked and fled the city. It was an army of ‘naked’ Frisians headed by Magnus that retook the citadel and the eternal city. In return Charlemagne offered wealth, weapons, treasure and more. Magnus’ choice, however, was that all Frisians would be free and not subordinate to anyone else except, of course, to the Holy Roman Emperor himself. Charlemagne granted this wise request and behold: the Charlemagne privileges or Magnuskerren. Choices that even have implications for today, who has to pay taxes and who actually not.
The Magnuskerren have many names, in many languages, like: Magnuskeuren, Karelsprivileges, Karlsprivileg, Friesische Freiheit, libertas Frisonica or Previlegii Frisiorum Caroli Magni. For the Frisians these privileges were the legitimization for the free-farmer republics of Frisia not to recognize anyone as their lord. Tota Frisia, as it is often named, stretched during the High Middle Ages from the region Westfriesland in the Netherlands to the River Weser in Germany. Sometimes even the non-Frisian, and also lord-free, region Dithmarschen was included. In other words: the Frisians (and Ditmarsians) claimed to be Reichsunmittelbar since the rule of Charlemagne.
And kas, that Fresan friheren were, thi berna and thi onberna, also lange so thi wind fan tha olcnum we, and thio wrald stode, and wellat wasa mith tha kere thes koninges hacha heranatan.
And [he] chose that Frisians freemen were, the born and the unborn, as long as the wind blows from the clouds, and the world stands, and with this choice they want to be the king’s high men.
A ker from Magnus-kerren is related to the current Mid-Frisian word kar which means ‘choice’. Kerren is plural.
At beginning of the High Middle Ages, the southern coastal zone of the North Sea had undergone an opposite development compared to the rest of Europe. Instead of developing feudal structures with government institutions, Frisia you could say ‘returned’ to the Germanic tribal social structures. Around 1100 this defragmentation process was completed in Frisia between the River Lauwers and the River Weser, the area what is today the province Groningen and region Ostfriesland. Besides Frisia, also the Saxon region of Dithmarschen underwent the same development. When in 1101 the Saxon Henry the Fat became Margrave of Frisia, the Frisians of (probably) current region Ostfriesland killed him immediately during his first visit, in an attempt of Henry to claim his rights, his gift. A clear statement of the Frisians. No foreign domination was accepted anymore in Ostfriesland. By the way, 1101 is the same year Count Floris the Fat of West Frisia renamed himself Count of Holland. The process of defragmentation and the shrinking of external influence (i.e. the bishopric of Utrecht) in the part of Frisia what is today province Friesland, took about one and a half century longer than the rest of Frisia. So, halfway the twelfth century the whole of Frisia was a lordfree area.
The result, among other, was that in the High Middle Ages every terp (i.e. artificial settlement mound, mostly found at the tidal marshlands along the Wadden Sea), every village, every farmer was basically free. No obligation to fight for any foreign lord, except for the Emperor. And then only limited to defend the territory of Frisia. Nor any obligation to pay taxes to counts and bishops alike. Having the right of possession too. Having the right to uphold their own laws and, moreover, to choose their own redjevas ‘judges’. Concerning those chosen judges, the name used in the sagas of the Charlemagne privileges is potestas frisae. This title and office was unknown in the wider region of northwestern Europe, but was similar to the thirteenth-century office of podestà in Italy. In the Italian city republics this was a chosen office of justice/judge, and at the same time that of commander during war.
Of course, the feudal and religious powers surrounding Frisia both close and from afar, thought quite the opposite with regard to the Frisian freedom. It were for example the thirteenth-century writers Melis Stoke from province Zeeland, and, especially, Jacob van Maerlant from Flanders, who were openly annoyed by this so-called Frisian freedom. Needless to say, they fully supported the claims of the counts of Holland on Frisia.
But what is true of these Magnuskerren?
Let’s start where it all began: the eternal city. We take you to one of the old churches in Rome, the Church of the Frisians (or Friezenkerk or Friesenkirche). Only a stone’s throw from the magnificant Saint Peter’s Basilica. Less than 100 meters to the Saint Peter’s Square.
Presence of the Frisians in Rome actually does date back to the time of the Magnus sagas. The oldest mention is of the Frisian schola in 799, when the schola welcomed back to the city Pope Leo III, who had lived in exile in Paderborn, Germany for six months. Scholae existed for the Saxons (schola Saxonum), the Franks (schola Francorum), the Lombards (schola Langobardorum) and the Frisians (schola Frisonum), and were established after these tribes had been Christianized. The schola Frisonum was the latest addition of the four, because initially the Frisians stayed at the schola of their neighbors the Saxons. The schola Frisonum is also mentioned in the Liber Pontificalis ‘Book of the Popes’.
A schola was a walled place where pilgrims could stay and where they had their own church, hospital and cemetery. The exception was the Saxons who used their own language to indicate a schola, namely burg. Today, the medieval city district Borgo, or I Borghi, still reminds of this old Saxon name. The Frisian schola was built on Janiculum Hill, 500 meters from the River Tiber, and overlooking the Grave of Saint Peter at the Vaticanum. The Vaticanum was the name of the level area between Vatican Hill and the River Tiber, and also known as Nero’s Plain.
Janus Head – The name Janiculum Hill is a reference to the pagan god Janus that was once worshiped. Janus had two faces. One looking to the past, and one looking to future. The god of all beginnings and of passage. Hence the month January. Images of Janus must have been present on this hill.
There is a Janus head to be seen in former Frisia as well. No kidding. Not on a hill top but -what else?- on top of a dike, at the town of Harlingen in province Friesland. Erected in 1576, it is the landmark to mark the end of long disputes between five districts concerning the maintenance of the sea dikes. On top of the stone pillar a two-faced Janus head is placed. It is nickname is the Stenen Man ‘man of stone’. Now we would name him super-hero ‘The Thing’. Harlingen will appear again in this blog post, see further below.
Back then you walked up the Janiculum Hill via a path called Vicus dei Frisoni, also named Borgo dei Frisoni. Everything, the scholae, was outside the medieval city walls of Rome, until 848. In this year the Vaticanum level area was included within the walls. Later in the sixteenth century, on the Vaticanum, the grand Saint Peter Basilica as we know it today, was built. Therefore, today the Church of the Frisians overlooks the impressive Saint Peter’s Square. A prime location. Furthermore, every schola also had its own militia to defend the schola. Pilgrims could join these militias. It were these militias that welcomed back Pope Leo III in the year 799. Another option as pilgrim or soldier, was to settle as farmer. The Frisians and the Saxons did that in the valley of Crepacore and near mountain Capricore, 40 kilometers north of Rome as the crow flies. The villages there also had there own militias called militiae rurales Sancti Petri.
Because of the Investiture Controversy, in 1084 Holy Roman Emperor Henry IV besieged Rome and installed antipope Clement III. Desperate Pope Gregory VII, the original, asked the Norman (or Viking, if you like) Robert Guiscard to help him out. He did. Henry IV had to retreat, and Pope Gregory was back in the saddle. It came with a very hefty price, though. Consistent with Viking tradition, Guiscard’s army sacked most of the city, including the scholae of the Frisians, the Franks, et cetera. All Frisians were killed as well.
Only two things remain today from the schola Frisonum. That is, firstly, a Latin grave inscription HEBI GENE FRISONO ‘Hebe of the Frisians’ who died there in the year 1004. Possibly a knight. The second thing that is still there to be admired, is the sweet water well. It is behind the Church of the Frisians, in the garden of the fathers Jesuits.
At the spot of the former schola and church, the Frisians built the Church of the Frisians which was consecrated in the year 1141. Its Romanesque bell tower, which stayed more or less unchanged ever since, is even the oldest of Rome. And although for some decennia the tower was mute, since the summer of 2019 the tower bells casted in the eighteenth century have been restored, and the church has joined the cacophony of ringing towers of Vatican City and Rome again. Other names for the church are San Michele dei Frisoni, San Michele in Sassia and Santi Michele e Magno.
There is a theory that at the end of the sixth century, Pope Gregory I founded eight churches dedicated to Archangel Michael after he had seen the angel above the mausoleum of Hadrian in Rome. It was a time the Plague swept through the region. The Archangel put his sword in the scabbot, a sign the Plague had ended. The Church of the Frisians is therefore one these eighth churches.
The church was thus dedicated to Archangel Michael, the first patrocinium of the church (see also featured image of this post). Indeed, the great artist and architect Michelangelo received his name from this angel too, and he is also famous for painting the Sistine Chapel ceiling of the nearby Saint Peter’s Basilica. Archangel Michael, however, was the leader of the army of God against evil, the angel of death, and responsible for weighing the souls after death. Therefore, Archangel Michael was associated with justice and righteousness too. The latter aspects correspond with the former Frisian pagan god Forseti, a god of justice too and worshiped at the North-Frisian island Heligoland in the north sea, and in southern Norway. However, in general, the Germanic god Wodan/Odin was replaced by the archangel Michael after Christianization.
But, a second patron for the church was coming up: Saint Magnus.
Saint Magnus is being worshiped in the towns of Fondi and Anagni in region Lazio in Italy, and churches are dedicated to him. Other churches in Europe dedicated to Saint Magnus are up north. Firstly, this is the church of Esens in the district Harlingerland in region Ostfriesland. Secondly, these are the churches of the villages of Bellingwoude in province Groningen, and of Hollum and Hoornsterzwaag both in province Friesland. Lastly, the church in the village Anloo in province Drenthe, is dedicated to Saint Magnus as well. In sum, Frisia and Italy. Now how did that all happen?
For this we turn to another, lengthier inscription preserved in the Church of the Frisians in Rome. To see it, go to the back of the church and look for it above a door at the left. It is the story about three Frisian soldiers serving in Charlemagne’s army, and who are on their way back to Frisia. This after a military campaign against the Saracens, i.e. the Muslims from northern Africa, in the region Apulia in the southeast of Italy. Their names are Ilderado from Groningen, Leomot from Stavoren and Hiaro from Slinga. Unclear where the village Slinga was located (see further below). It is then that the three men find the dead body of Saint Magnus of Cuneo. Magnus was a soldier of the Theban Legion in the Roman Period, in the third century. Later he became a martyr. No explanation is given as to why the body is there. The men decide to take the body to Frisia. When they are near the town of Sutri, north of Rome, the body refuses to be taken any further. In their dreams, the men were told to bring the body to their church in Rome. So, they did. And so, the Church of the Frisians got its second patrocinium, and hence its double name, Michael and Magnus.
Because of the three man’s devotion, they were allowed to remove a part of the arm of Saint Magnus to serve as a relic back home in Frisia. Pieces of the arm were apparently spread over the villages of Anloo, Bellingwoude, Esens, Hollum and of Hoornsterzwaag. How relics, if they did, ended up from the church in Rome in the churches of Anagni and Fondi, is not told. The church of Anloo, by the way, when it was renovated, turned out to have been built over a building dating to the Roman Period. A pattern of stone column supports have been found, originally supporting a wooden structure.
Because the full text of the inscription is not easily accessible on the web, it is presented below for the non-believer, or simply the connoisseur, with a translation (Verweij, 2014). The tekst is full of abbreviations, so hard to read.
IN NO DNI TEMPORE LEONIS IIII PP IPATE CARVLO MAGNO IPATORE EO TEPORE QVO PETRI BASILICA A SARRACENIS CAPTA FUERAT, TVNC DENIQ P TOTIVS MVNDI CAPITE TVRBATO TOTVS MVNDVS TVRBATVS OMIS GALLIA CV REGE CARVLO AD TVENDV ILLA VENERVNT. VNDE CNTRA INIMICOS DNI BELLA DNI DECERTANDO QDAM MORTVI S ET IN CRIPTA IVXTA NERONIS PALATIVM SEPVLTI, EODD TEPORE A LEONE PP ET REGE K AD HONORE MICHAELIS ARCGLI SUP ILLOS FACTA EST ECCLA. HIS ITA PACTIS REX APVLIA ABIIT EAQ BEATO PETRO ET ROME SVBIVGAVIT. P IDE TEPVS EXERCITV GALLIA REVERTENTE TRES ILLORV MILITES DE FRISIA ILDERADO DE GRONINGA ET LEOMOT DE STAVERA ET HIARO ET CELDVI ANCILLA DEI DE SLINGA. HI BEATI MAGNI CORPVS IN LOCO Q DICIT FVNDI INVENER. QVO INVENTO IN ILLORV PVINCIA PORTARE ET CDIRE DECREVER SED DIVINA GRA COHOPANTE POSTQVA AD SVTRINAS PARTES VENT E APLIVS DEFERRE N PVALVER QA BIS ET TER TERRITI ET P SONIV MONITI ROMA REVERTENTES SCVM CORP SECV TVLER VNDE FACTV E QVOD ILLORV DEVOTIONIS CAVSA PARTE BRACHII A SE SEGREGARI AB ILLIS PMISIT. PARTES AVTE CETERE IN CRIPTA PFATA REMANSER SUP QVA SICUT DICTV EST ECCLA IA FVERAT FACTA DEINDE OMNI ANNO SIMVL BENEFICIV OPTIMV DARI IBI DECREVER SCILICET TRECENTAS MARCAS ARGENTI P ILLORV ET VBIQ REQESCENTIV REDEPTIONE ET IM PERPETVV SEV DIVITES SIVE PAVPERES IN EADE SVPRA DICTI ARCHANGELI BASILICA ET BEATI MAGNI ECCLA IVXTA EA AB EISDE CONSTRVCTA HOSPITALIA QVANDO A SVIS PARTIBVS VENIRENT AGERENT. IDCIRCO NROR ALIORVQ OMIB PATEAT SI IPSI VEL QCVQ HOC DECRETV RVPE TEPTAVERINT SCIANT SE PPETVO DAPNATOS ET MALEDICTOS ET PREDICTI PONTIFICIS ANATHEMATIS VINCVLIS IN INFERNO NISI RESIPVERINT CV DIABOLO CLIGATOS, IN HAC AVTE VITA MISEROS PAVPES ET DISPSOS ET ITERV DE LIBRO VITE CELESTIS DELETOS ET DE REGNO XRI DEIECTOS. CONFIRMATORIB FAVTORIB HVI DECRETI EC TR SIT BENEDIC XRI ET FRVANT VTRIVSQ VITE GAVDIIS AM
In the name of the Lord. In the time of Pope Leo IV when Emperor Charlemagne was emperor, at that time when Saint Peter’s Basilica was taken by the Saracens, when finally, the whole world was confused, all of Gaul came with King Charles to protect her. When a few died fighting with the Lord’s war against the Lord’s enemies and were buried in a crypt next to Nero’s palace, Pope Leo and Charlemagne in honor of Archangel Michael built a church above them. When all this was done, the king went to Apulia and submitted it to Saint Peter and Rome. At the same time, when the army returned to Gaul, three soldiers from Frisia, Ilderado from Groningen, Leomot from Stavoren and Hiaro and the maidservant of the Lord Celdui from Slinga, found the body of Saint Magnus in the place called Fondi. When they found this, they decided to carry it to their region and bury it there, but with the help of God’s will they could not carry [the body] any further after they had come close to Sutri. They were frightened two or three times and warned in a dream, they returned to Rome and brought the body with them. Because of their devotion [the Pope] allowed them to separate part of his arm from the body. The other parts, however, remained in the above crypt above which, as stated, a church was already built. Then they decided that every year a very great gift would be given, namely three hundred marks of silver for the redemption of themselves and for those who rested there, so that for ever rich or poor would stay in the aforementioned basilica of the archangel and church of Saint Magnus in the hospital they built next to it, if they came from their regions. That is why it is clear to all of us and to everyone else that if they try to break this decision, they must know that they will be condemned and cursed forever and will be bound by the anathema of the aforementioned pope with shackles in hell and sit together with the devil unless they come to their senses, and will be miserable, poor and scattered in this life, and will be nullified from the book of heavenly life and expelled from the Kingdom of Christ. For those who confirm and favor this decree, etc. blessed by Christ and may they enjoy the joys of both lives. Amen.
The dating of the inscription is not very precise. The inscription itself talks about Charlemagne and Pope Leo IV, and the time the Saint Peter’s Basilica was sacked by the Saracens. That points to the year 848, when the Saraceni attacked Rome and were defeated by Germanic armies, including the Frisians. In that same year, the Saracens were chased all the way south to Apulia. Charlemagne, however, could not be part of this history, since he was already dead by the time Leo IV was pope (847-855). Besides, if 848 is indeed the correct year of the story, it means Pope Leo was dead by then too. Anyhow, based on the ‘financial’ passages of this inscription concerning the gift, scholars date the inscription itself the first quarter of the eleventh century. Thus testifying about events which took place almost two centuries before.
So, now we have the ingredients. Saint Magnus, Frisians in Rome, Charlemagne, fighting against the Saracens, and Archangel Michael. Take a blender and press on button 3 for a maximum effect to create the saga of the Frisian freedom. Or, as they said back then: ‘fry ende freesk’ (free and Frisian) or ‘fry freesk’ (free Frisian), a slogan dating back to the eleventh century (Vries, 2012).
This is the smoothie you get
In all the different versions of the Magnus saga, the Frisians fighting against the citizens of Rome, the Saxons and the Saracens, or a combination thereof. Always to free Rome for the sake of Charlemagne and the Pope. Besides this, the Frisians supposedly fought like true biblical Urías in the frontline, and under command of their leader Magnus who carried a red banner. Apparently, Saint Magnus was transformed from an Italian bishop into a Frisian warrior. Also, the Frisian warriors are described as ‘naked’ in the sagas, what is meant by that they did not wear (heavy) armor and helmets. This corresponds with the images preserved of high-medieval, barefooted Frisian warriors: read our blog post Foreign Terrorist Fighters from the Wadden Sea. where we elaborate on their appearances. Lightly armed and fast in charging at the enemy. Even their hair shaved off. All versions of the saga also have in common that the Frisians were rewarded for their heroic deeds and achievements by Charlemagne himself. Sometimes the freedom was pro-actively given to them, although mostly it was chosen by their leader Magnus: the so-called Magnuskerren. And, the Magnuskerren were laid down in a charter together with a seal of Charlemagne and brought to Frisia by Magnus, together with the red banner.
Sources of the sagas – The saga of the Frisian Freedom, with different accents, has been codified in several Old-Frisians law books: Codex Unia (U), ca. 1650; Scripture of Fivelgo (F), ca. 1450; Jus Municipale Frisonum (J), ca. 1530; Druk (D), ca. 1485; First Hunsingo Codex (H), early-fourteenth century; Codex Aysma (A), sixteenth century.
To makes things more credible concerning the freedom saga, a serious Magnus pedigree was constructed over time too. He received a totally fictional genus name, namely Forteman. He also got his own seal. Furthermore, Magnus Forteman supposedly was the first duke of Frisia. And, while they were at it, and why not?, his father Gustavus founded the first church in Frisia, at the village of Harlingen. The church at Harlingen, originally built around the year 1200, has Saint Michael as patron. Also, the coat of arms of Harlingen carries the image of Saint Michael.
Almenum – The present-day town of Harlingen developed from the terp settlement of Almenum. On this terp stands the church of Saint Michael. The name Almenum -still being used- might indicate a pre-Christian origin of a temple or sanctuary at this spot. The morpheme ‘al’ stems from ‘al(a)h’ meaning temple, and ‘alhist’ meaning ‘dwelling near the temple’. Other place names in the Netherlands with a similar origin are Aalst and Elst (Van Eijnatten, 2005).
Other morphemes that point towards a spot of pre-Christian sacral relevance, are ‘harg’ meaning temple or hilltop sanctuary, like the villages of Hargen in province Noord Holland, Harich in province Friesland, and ‘wîha’, meaning holy place, idol or altar, like the village Wehe-Den Hoorn in province Groningen, or the towns Wijhe in province Overijssel, and Wije in province Gelderland. Old English has similar names, namely ‘hearg’ and ‘wēoh‘, which can be found in the epic poem Beowulf (Mees, 2019).
There is even a theory that Hiaro of Slinga, one of the three soldiers who find the body of Saint Magnus (see above, the inscription in the Church of the Frisians in Rome), is actually from Hlinga. The ‘S’ of Slinga would be a slip of the chisel, which in turn stems from Harlinga and thus Harlingen. Together with a thirteenth-century seal from shire Wonseradeel in province Friesland, which depicts a warrior with the eagle of Charlemagne (possibly indeed Hiara from Slinga) and bearing the text Sanctus Magnus dux Frisonum ‘Saint Magnus duke of Frisia’, a fusion was made of the historic persons Hiaro and Magnus (Van Buijtenen, 1953). We are, however, not sure simply another saga has been created with this ‘historical theory’. It needs quite a lot brain gymnastics, to be frank. And how to incorporate Harlingen’s older place name Almenum, we do not know either, based on this creative outburst of Van Buijtenen.
Of course, the whole early-medieval story about the Magnuskerren and Magnus is fake news. Still, it constituted a crucial part of high-medieval Frisian society to withstand the claims of non-Frisian, feudal and ecclesiastical rulers to incorporate Frisia into their jurisdiction. As said earlier, Frisia was a collection of countless free-farmer republics and its defense fully relied on people, on citizens, on farmer militias. These legends and sagas helped to motivate and organize themselves. Nowadays, the Mid-Frisians would call that mienskip. The many little republics were loosely united within the almost mythical but beautiful named saun zelanden ‘Seven Sealands’. Later, at the beginning of the thirteenth century, the small republics tried to strengthen their alliance with the Upstalsboom treaty. The Upstalsboom had its own seal (too) with an image of Charlemagne sitting between two Frisians warriors. The man, Charlemagne, keeps popping up. When the Frisians and their chosen judges gathered at the hill of the Upstalsboom once a year on Pentecost, the motto spoken was eala Frya Fresena ‘stand up/hail free Frisians’. The alliance of Upstalsboom failed ingloriously, however. Read our post Upstalsboom: why solidarity is not the core of a collective to know why and how.
There might be some truth in it after all
In 1234, William II, son of Count Floris IV of Holland, became the new count of Holland and Zeeland, i.e. most of former West Frisia. In 1248, Count William fought against the excommunicated Emperor Frederick II and conquered among other things the city of Aachen. Curiously, it were Frisians who fought under his banner. The same year, William II was crowned as Holy Roman Emperor. Two days after his coronation in the Aachen Cathedral, he gave privileges to the Frisians who were gathered in the cathedral too. Actually, William II reconfirmed -in a charter- the rights, freedoms and privileges that Charlemagne already had given to the Frisians. So, Emperor William made a connection again with Charlemagne and that era.
Whatever the privileges for the Frisians, the Westfriesen of current region Westfriesland in the Netherlands, who were in a bitter conflict with the sutherna here ‘southern lords’ (i.e. counts of West Frisia/Holland) for centuries already, slaughtered William II without hesitation in the cold winter of 1256. This was during a military expedition in region Westfriesland. Read also our blog post In debt to the beastly Westfriesland about the history of the free-farmer republic Westfriesland, and their struggle with the counts of West Frisia/Holland.
Then, in the winter of 1417, Holy Roman Emperor Sigismund extended (again) to universorum Incolarum et inhabitantium tam Orientalis quam Occidentalis frisie ‘all people and inhabitants of East and West Frisia’ the freedom privileges for real. Although not from Charlemagne, still from an emperor. The charter with a big seal has been preserved. Despite Sigismund’s generous ruling the Frisians do pay taxes to the German and Dutch governments today. Maybe they should make a case at court with Sigmund’s charter as their inalienable right.
Parallel to the decline of Frisia, the Church of the Frisians in Rome fell into disuse in the Late Middle Ages, and the Chapter of Saint Peter took possession of the church. In 1989 the Netherlands received the user right of the church, based on the historic ties. Although that could have been just as well the State of Niedersachsen, we add. The church council of the Church of the Frisians is called the Willibrord Council, the early-medieval missionary of Frisia. In 1995 Pope John Paul II consecrated the altar of the renovated church. And, whatever the user right for Frisia, Niedersachsen or the Netherlands, when you are in Rome to visit the Church of the Frisians, do not forget to take a quick look at Saint Peter Basilica too. It is worth it.
Note. The Ostfriesen, or East-Frisians, have a different legend as to how they received their freedom. That was after the battle of Norditi in 884, also known in Germany as the Normannenslacht. It was a battle (some argue several battles) between the Frisians and the Danes who had occupied the coastal zone of Ostfriesland. As a sign of gratitude for pushing out the Vikings, King Charles the Fat gave the Frisians their freedom. Read our post A Theelacht. What a great idea! for more details on this battle.
Suggestion for further reading:
- Abernethy, S., The schola Saxonum and the Borgo in Rome (2019)
- Blok, P.J., De Friezen te Rome (1902)
- Bremmer, R.H., “Thi Wilde Witsing”: Vikings and Otherness in the Old Frisian Laws (2020)
- Bolhuis van Zeeburgh, J., Kritiek der Friesche geschiedschrijving (1873)
- Eijnatten, van J. & Lieburg, van F., De Nederlandse religie geschiedenis (2005)
- Folkerts, R., Die Theelacht zu Norden. Ein seit 1100 Jahren auf genossenschaftlicher Basis geführter Familienverband (1986)
- Israel, J., Friesland and the Rise of Democratic Republicanism in the Western World (1572-1800) 2019
- Mees, K., Burial, Landscape and Identity in Early Medieval Wessex (2019)
- Molen, van der S., Oorsprong en geschiedenis van de Friezen (1981)
- Muskens, M.P.M., De Kerk van de Friezen bij het Graf van Petrus. De geschiedenis van de kerk. De kerk in de geschiedenis (1989)
- Schuur, J.R.G., De Friese hoofdeling opnieuw bekeken (1987)
- Schuyf, J., Heidense heiligdommen. Zichtbare sporen van een verloren verleden (2019)
- Siefkes, W., Ostfriesische Sagen und sagenhafte Geschichten (1963)
- Steensen, T., Die Friesen. Menschen am Meer (2020)
- Tuuk, van der L., De eerste Gouden Eeuw. Handel en scheepvaart in de vroege middeleeuwen (2011)
- Verweij, M., De zusterkerk van Anloo: de SS. Michele e Magno te Rome, Magnuslezing (2014)
- Vries, O., Asega, is het dingtijd? De hoogtepunten van de oudfriese tekstoverlevering (2007)
- Vries, O., De taal van recht en vrijheid. Studies over middeleeuws Friesland; Die Friesische Freiheit; ein Randproblem des Reiches; De Aldfryske pearformule fry ende freesk (2012)
- Waterbolk, H.T., Profane en sacrale houten gebouwen uit de Middeleeuwen in Noord-Nederland (2002)