The Ancient Egyptian god Osiris was the patron of death, fertility, and life. Osiris was worshiped in Egypt as early as 2500 B.C. and is considered one of the oldest Egyptian gods. He is often portrayed with green skin which to the Ancient Egyptians meant rejuvenation.
Osiris is said to be the husband and brother of Isis and the father of Horus. In the Ennead version of Egyptian Mythology it is said that, " Osiris was originally the god of the underworld and the dead, in which he was one of the four children of the earth (Geb) and the sky (Nuit), and was the husband of Isis, who represented life. As god of the dead, Babi, the god who devoured unworthy souls, was described as his first-born son." As with Isis and Hathor, there is much speculation regarding their legends and origins.

Quote from: http://www.egyptian-gods.net/osiris.php