Centuries after the
fall of the Western Roman Empire, Charlemagne, who had conquered much of its former territory, announced its
restoration. Upon his death, he passed this realm to his son Louis the Pious, who in turn passed it to his firstborn son Lothair I. However, the latter's brothers—Charles and Louis—refused to recognize him as their suzerain. When Lothair attempted to invade their lands, they allied against him and defeated him at the
Battle of Fontenoy in June
841. Charles and Louis met in February 842 near modern
Strasbourg to affirm their alliance by swearing a joint oath against Lothair. The following year the civil war ended with the Treaty of Verdun, in which the three claimants partitioned the Empire amongst themselves. The Oaths were not preserved in their original form, but were copied by the historian
Nithard, another grandson of Charlemagne, in a work titled
De Dissensionibus Filiorum Ludovici Pii "On the Quarrels of Louis the Pious' Sons". This was a firsthand account, as Nithard had campaigned alongside his cousin Charles the Bald. It was however biased, reflecting the perspective of the allies and casting Lothair as an aggressor and villain. Louis and Charles swore their oaths not as kings—a term which is never used—but rather as lords, with their respective entourages acting as witnesses. Ostensibly they were acceding to Lothair I's demands as his future 'subjects'. Although the Oaths are of little political importance, given that they were superseded by the more comprehensive Treaty of Verdun, they are of significant importance to the field of linguistics. As the scholar Philippe Walter wrote: == Manuscript ==