There is no text mentioning the place or date of his meeting with Hadrian. 
In all likelihood, it took place in the winter of 123 or spring 124, during the emperor's visit to Claudiopolis. He then became Hadrian's favorite. 
His presence in the imperial entourage was not officially mentioned until 130, during Hadrian's trip to Egypt. In October 130, he drowned in the Nile, in the Hermopolis region, under mysterious circumstances. Several explanations have been put forward since ancient times. Hadrian himself evokes a simple accident, but many authors see it as a ritual sacrifice in which Antinous would have served as a voluntary victim, either to prolong Hadrian's days or for divinatory practices. Hadrian is very affected by the death of his favorite. For their part, the Egyptians divinize the young man: they see in the Nile drowned the servants of Osiris. A city is even founded on the river, Antinoupolis. 

Hadrian encouraged the development of the new religion by multiplying the works of art bearing the image of the young man. The Greeks also recognized in Antinous an avatar of Hermes. In 131-132 the Antinoeia, games reserved for ephebes combining gymnastics and musical competitions, were founded. 
Its name is given to a constellation made up of five stars of the present constellation of the Eagle. In Rome, worship also eventually took hold. This will be the last great cult introduced before the arrival of Christianity. Last cult of love.