Hymen or Hymenæus, the son of Apollo and the muse Urania, was the god who presided over marriage and nuptial solemnities, and was hence invoked at all marriage festivities.
There is a myth concerning this divinity, which tells us that Hymen was a beautiful youth of very poor parents, who fell in love with a wealthy maiden, so far above him in rank, that he dared not cherish the hope of ever becoming united to her. Still he missed no opportunity of seeing her, and, upon one occasion, disguised himself as a girl, and joined a troop of maidens, who, in company with his beloved, were proceeding from Athens to Eleusis, in order to attend a festival of Demeter.
On their way thither they were surprised by pirates, who carried them off to a desert island, where the ruffians, after drinking deeply, fell into a heavy sleep. Hymen, seizing the opportunity, slew them all, and then set sail for Athens, where he found the parents of the maidens in the greatest distress at their unaccountable disappearance. He comforted them with the assurance that their children should be restored to them, provided they would promise to give him in marriage the maiden he loved.
The condition being gladly complied with, he at once returned to the island, and brought back the maidens in safety to Athens, whereupon he became united to the object of his love; and their union proved so remarkably happy, that henceforth the name of Hymen became synonymous with conjugal felicity.
From: Berens, E.M. The Myths and Legends of Ancient Greece and Rome. New York: Maynard, Merril, & Co., 1880. Text in the public domain.