Antinous was a Bithynia Greek born in Claudiopolis the Roman province of Bithynia (present-day Bolu, Turkey). In 123 AD Hadrian met Antinous and had him taken to Rome for a higher education.
Hadrian formed a relationship with Antinous, and by 128 AD he was the favorite of Hadrian.
In 130 AD Hadrian visited Egypt with the imperial entourage including Antinous. While on the river Nile Antinous drowned at the same time Egyptians were commemorating the drowning in the Nile of the God Osiris.
How he drowned is unknown, speculation is that he committed suicide or sacrificed himself to prolong the life of the emperor.
Hadrian was profoundly affected by Antinous death. He encouraged the deification of Antinous and a new cult. Hadrian had a large temple and a new city of Antinopolis built on the banks of the Nile.