In 308, probably April, Maximian tried to depose his son in an assembly of soldiers in Rome; surprisingly to him, the present troops remained faithful to his son, and he had to flee to Constantine. In the conference of Carnuntum, in the autumn of that same year, Maxentius was once again denied recognition as legitimate emperor, and Licinius was appointed Augustus with the task of regaining the usurper's domain. Late in 308, Domitius Alexander was acclaimed emperor in Carthage, and the African provinces seceded from Maxentian rule. This produced a dangerous situation for Maxentius, as Africa was critical to Rome's food supply.