He devoted the following year to suppressing Mesopotamia and other Parthian vassals who had backed Niger. Afterwards Severus declared his son Caracalla as his successor, which caused Albinus to be hailed emperor by his troops and to invade Gallia. After a short stay in Rome, Severus moved north to meet him. On 19February 197 at the Battle of Lugdunum, with an army of about 75,000 men, mostly composed of Pannonian, Moesian and Dacian legions and a large number of auxiliaries, Severus defeated and killed Clodius Albinus, securing his full control over the empire.