https://www.britishmuseum.org/collection/object/C_1844-0425-1609

Antinous accompanied Hadrian during his attendance of the annual Eleusinian Mysteries in Athens, and was with him when he killed the Marousian lion in Libya, an event highly publicised by the Emperor. In October 130, as they were part of a flotilla going along the Nile, Antinous died amid mysterious circumstances.[7] Various suggestions have been put forward for how he died, ranging from an accidental drowning to an intentional human sacrifice or suicide.

The way that Hadrian took the boy on his travels, kept close to him at moments of spiritual, moral or physical exaltation, and, after his death, surrounded himself with his images, shows an obsessive craving for his presence, a mystical-religious need for his companionship.

— Excerpt from Royston Lambert’s Beloved and God: The Story of Hadrian and Antinous[30]