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 would in turn pass 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 would end with the Treaty of Verdun, in which the three claimants partitioned the Empire amongst themselves.