Its important to
note that by this time in Roman history, nearly every emperor following
Alexander was deified by the Senate as standard practice. In reality, only
a very few were not deified up to this point (Tiberius, Caligula, Nero,
Commodus and various usurpers). The practice largely continued until the
reign of Constantine in the 4th Century AD. At this point the growth of
the Imperial cult ceased as the state religion slowly shifted to monotheism
(Mithraism, Sol Invictus and Christian).