Zuckerman argues that the Princedom played an important role as a buffer zone in the border area between the Muslim caliphate south of the Pyrenees and the Christian Frankish Empire in the north.

[1][2] Zuckerman's thesis has been contested by several scholars and criticized for its conjecture and lack of reliable evidence, particularly when identifying presumably Christian Carolingian nobles with Jewish members of the House of Exilarchs.

[3][4][5] Zuckerman analyzed monastery records, Carolingian archives, Jewish medieval texts from Europe and Babylonia, Muslim sources, Chanson de geste (heroic songs) and other primary documents.

Zuckerman used a holistic, multicultural approach to sources originally in Hebrew, Aramaic, Latin, Greek and Arabic with attention to Jewish, Christian and Muslim practice and international political alliances in Europe, the Orient and North Africa in medieval times.

[7] The geographical and cultural mobility of Jews in post-Exilic period led to such widespread practice of combining traditional Jewish names with kinnui'im (secular nicknames).

Against this practice it is for example argued that Makhir of Narbonne, the most multicultural personality of the dynasty, had Hebrew, Aramaic and Frank names even combined with a further nickname based on Chanson de geste.

Creating a vassal Jewish princedom, intermarrying with its Davidic line and building a strategic alliance with the Abbasid Caliphate in Baghdad who ruled over the land of Israel provided Charlemagne a symbolic hold in Jerusalem which fulfilled both preconditions.

Theodoric was granted by the Carolingian broad authority over Jews and Christians, extensive hereditary territories and "a great possession", including former church property lost decades before to the Umayyad Caliphate.

It refers consistently to Makhir and his descendants as a dynasty of nesi'im princes whose power and position in Narbonne were virtually identical with that of the exilarchs (k'mo rashe galuyot) in Babylonia.

[14] As Zuckerman relates, this assignment of "a great possession" was immediately sharply protested by Pope Stephen III, to no avail, in a papal epistle dated 768 complaining bitterly about gift of money and cession of territory to the Narbonne Jewry.

[15] Zuckerman finds what he considers to be a corresponding claim of a great endowment in favor of a Jewish scion of royal lineage from Baghdad in the Gesta Karoli Magni ad Carcassonam et Narbonam.

[16] A Jewish principate in Septimania would have represented a significant theological challenge to the church during its whole existence and Zuckerman sees its aftertaste as still perceptible even in the 12th century after the Princedom lost most of its real power from the Carolingian era.

His magnificent physical strength was distinguishing and William probably joined his father Makhir-Theodoric in Charlemagne's campaigns in the East, which left the Septimania area unprotected and weakened by Makhirs dead.

However the Franks deliberately delayed the triumphant entry to the city till Sunday 19 October 803 to avoid desecration of "the Holly Sabbath", where unnecessary military activity is forbidden under Jewish law.

King Louis joint the end of the siege and gave Bera command of the newly captured fortress enabling William to return home to Narbonne or Toulouse.

In fact it must be assumed that later court chronicles were carefully editing out evidence[32] about the constructive role of the Makhiri dynasty and calling attention to Jews "only under circumstances which compromise their loyalty or depict them as enemies of Christianity".

[34] As nasi William founded a library and academy of Jewish learning in Gellone – Bet-El (Casa Dei) which had also commercial and military functions, and where he probably spend the last years before his death around 823.

Bodo fled to Spain, changed his name to Eleazar, married a Jewish woman, engaged in literary debate with Albar of Cordova, which is also viewed as related to the Makhiri role in Frankia.

This Salomon-Bernard is said to have married to the daughter of William, Count of Toulouse (or his sister),[53] and Zuckerman thinks he was probably not of direct Makhir lineage but he emerged as the leader of the dynasty after the disastrous deaths of the Bernards relatives.

[53] In Zuckerman's narrative, after Bernard's execution, the Jews who until then were highly efficient protectors of the Spanish frontier felt that King Charles the Bald had broken their pact.

The grateful king, in anticipation, reconsidered his attitude towards the Jewish community and to the frustration of the Bishops Hincmar and Amolo, rejected in 846 at Diet of Épernay their anti-Jewish pro-ecclesiastical program and returned to the old political arrangements.

Zuckerman sees archbishop Hincmar of Rheims as the leading spirit behind taxing Jews and restitution of former ecclesiastical properties, and his death in 882 as opening the way for a more favorable ruling in 883.

In the South he achieved similar glory to his ancestors William of Toulouse and Theodoric of Narbonne, perhaps even surpassing them as he is reputed to have been a virtual king of his own domain: occasionally in the ninth century, Septimania is referred to as a "kingdom".

William was over time unable to retain the large inheritance, and Wilfred the Hairy took control of at least part of the Hispanic March, which territory Zuckerman sees as significant for the office of nasi.

[68] Zuckerman thinks it possible that Vita S. Austremonii refers to Margrave William as the Princeps Judaeorum – Prince of the Jews, becoming extremely angry after the Saint baptised his son Boso.

[70] Zuckerman's research follows what he sees as these Jewish princes until the tenth century, where their traces are lost in the chaotic conditions that marked the decline and eventual end of Carolingian rule.

[73] In 1972 Salo Wittmayer Baron wrote a foreword to the first edition of the Princedom, hoping that it will lead to reexamination of the source materials and much-needed extended scholarly debate about the dark period of Narbonnese Jewry.

[76] In 1982 Moncreiffe in his compilation of the British royals' genealogy mentions the difficulty to undertake genealogical research outside of Christendom, but portrays the conclusions of Zimmerman and the earlier work of Kelley as having a "strong probability", making a "good case" for identifying Makhir of Narbonne of the Royal House of David with Theuderic, Duke of Toulouse and making him ancestor of Arnaud 'manzer', Count of Angoulême, himself the forefather of Queen Isabella of Angoulême, mother of King Henry III of England.

In 1997, Taylor added to the prior published criticism a more general rejection of the idea of a Jewish Princedom and Makhiri dynasty, and lamented its spreading into genealogical circles.

However, his strongest rejection addressed Zuckerman's postulated correlation of the "real or imagined" dynasty of Jewish leaders with the historically-documented family of Count William of Gellone and the related onomastic evidence.