This is a statue of Caesar Augustus, a Roman Emperor. In Rome, Emperors were at the top of the social hierarchy. Of course, this only applies to imperial Rome, as emperors did not exist when Rome was a Republic.
Poseidon was one of the Twelve Olympians in ancient Greek religion and myth. He was god of the Sea and other waters; of earthquakes; and of In pre-Olympian Bronze Age Greece, he was venerated as a chief deity at Pylos and