Whilst the adoption of a single currency by 11 countries on January 1st 1999 was meant to contribute to a strengthening of European construction, after other measures of an economic nature, the expansion of Christian doctrine and culture quite obviously contributed to the unification strategy of first the Frankish kingdom and then the Frankish Empire under the Carolingians. Much as is the case for the current turmoil sweeping the Euro zone, rendering Christian faith uniform in the 8^th to the 10^th centuries around belief in the doctrine of the Trinity did not come around without difficulty. It nonetheless benefited from the battle Charlemagne embarked on with determination in the defence of Western Christendom.  

It is difficult to imagine today just how intense were the theological debates carried out in the Frankish court, successively under Pippin III the Short (King from 751 to 768) and under his son Charlemagne (King from 768 to 800, then Emperor up until his death in 814). This ebullience in theological thought, in which politics obviously played its part, essentially turned on the question of the Trinity, at a time when this dogma was far from having established itself within the heart of the Christian people. It was to follow step by step the friction caused by this doctrine of the Trinity, whilst equally examining its impact on the embryonic unity of the kingdom and then the Empire, that Florence Close, Assistant at the University of Liège’s History of the Middle Ages Department, rigorously applied herself in her book (1).

Happily, in her Prolegomena, she establishes several signposts which are aimed at contextualising, through a return to the past, the subject she sets out to unravel. First of all, she reminds us, it has to be remembered that ‘ancient societies did not distinguish between political power and religious power,’ because ‘the Emperor was not only an army General and a Magistrate, but also a holy figure, a Pontiff.’ Despite the fall of the Western Roman Empire in 476, that of the Orient surviving to the east of the vast ensemble built up over the centuries, the Bishop of Rome continued, at a distance, his collaboration with the imperial authority located in Constantinople, fighting to establish himself, in the name of the supremacy of the patriarchate of Rome over those of Constantinople, Jerusalem, Antioch and Alexandria, as the guardian of Orthodoxy within the realm of theological quarrels, in the face of imperial stances on these issues often termed heretic. Bringing to an end the dynasty of the Merovingians following a coup d’état carried out in 751, Pippin III the Short found in the unction received from the hands of Pope Stephen II (752-757) that he protect the  Lombards the necessary legitimisation for his contested royal power; a key event, dating to 754, which sealed the Frankish-papal alliance. From this day onwards, the Frankish king maintained a personal relationship with the Bishop of Rome; this entente cordiale would continue under their respective successors. The Frankish-papal alliance had its complete fulfilment when, at Christmas in the year 800, Pope Leo III crowned Charlemagne Emperor in Rome. The Western Empire – consisting of Gaul, Italy and Germania, but not Spain – was thus recreated under the impetus of the Bishop of Rome, a feat which failed to please the Basileus.

(1) Uniformiser la foi pour unifier l'Europe. La pensée politico-théologique de Charlemagne (Volume LIX, Bruxelles, Académie royale de Belgique, 2012)