Battle of Milvian Bridge The underlying cause of the battle was
the five-year-long dispute between Constantine and Maxentius
over control of the Western Roman Empire. Although Constantine's
father, Constantinus Chlorus, was the Western emperor, the
tetrarchial system in place at the time did not adhere to
primogeniture. When Constantius died on July 25, 306, his
father's troops proclaimed Constantine as Augustus (the Latin
honorific for emperors, roughly meaning "venerable"). But in
Rome, the favorite was Maxentius, the son of Constantius'
predecessor Maximian. Both men continued to vie for the title,
however a conference to resolve the dispute in 308 resulted in
Maxentius being named a senior emperor along with Galerius.
Constantine was allowed to maintain rule over provincial Britain
and Gaul, but was officially only a "Caesar"—a little emperor.
By 312, the two men were engaged in open hostility with one
another, although they were brothers-in-law through
Constantine's marriage to Fausta, sister of Maxentiu