Osiris and Isis
There are several versions of Osiris' life and deeds: the following is a basic summary:
Osiris was murdered by his brother, Set, who then chopped the body into smaller pieces. Isis and Nepthys, her sister, found the pieces (except his penis, which had been eaten by the Oxyrhynchus fish) and gave wax models of them to the priests to worship. Re sent Anubis and Thoth to mummify Osiris and Isis brought life back into his body. Afterwards, Osiris had to stay in the underworld and judge the souls of the dead and was called Neb-er-tcher ("lord of the outermost limit").
In Duat, the underworld, Osiris weighed the dead souls against the Feather of Truth. Souls weighted down by sin were devoured by Ammit and those who were light enough were sent to Aaru.
The Egyptian Ministry of Tourism website says that Orisis "once possessed human form and lived upon earth, and that by means of some unusual power or powers he was able to bestow upon himself after the death a new life which he lived in a region over which he ruled as king, and into which he was believed to be willing to admit all such as had lived a good and correct life upon earth".
The hieroglypic rendering of this God's name is still uncertain. Current thinking is that it is pronounced "aser" where the "a" is a glottal stop much as you still hear in the modern Arabic and Hebrew languages.
The mythos of Osiris, Isis, Horus and Set are among the most powerful in Egyptian mythology.
Osiris taught men how to farm the land and make wine and he was much loved by the people. Set was envious of his brother and so conspired to kill him. He secretly had a coffin made especially for his brother and then held a party inviting his unced that he would give it away to whoever it fitted. A few people tried the coffin, but alas they did not fit. Set encouraged his brother Osiris to try the coffin. As soon as he lay back the lid was slammed down and sealed shut! Set and his cronies carried the coffin to the Nile and threw it in, drowning Osiris. This action came to represent the annual flooding of the Nile.
Isis with the help of her sister Nephthys brought him back to life using their magical powers. Before revenge could be brought upon Set he struck again and this time dismembered Osiris into thirteen parts (some accounts say fifteen) and hid them thoughout the land. Isis searched the land for the pieces and spent many years doing so for Set had hidden them well, but she was not able to find all of them. The missing piece was his member, but she put together what she had and once again brought Osiris back to life.
This time she took no chances and kept him hidden until he had made her pregnant. Isis's magic could not keep him alive like this for too long and he died once more. The other gods decided to make him king of the underworld where he reigned over the dead but not before his death had been avenged.
The son of Osiris and Isis was Horus, who from birth sought to avenge his father's murder. He was brought up in secret in the marshes of the Nile delta. As soon as he was old enough the two met in battle. The fight was long and bloody; Horus lost one of his eyes in the battle and Set lost a testicle.
The conflict was brought before the rest of the gods. They decided in favor of Horus and gave kingship of the country to him. Set was condemned as the evil one and banished to the outlands. In other versions the two deities were reconciled and represented the union of Upper and Lower Egypt.
Some information used in this article came from the Egyptian Ministry of Tourism's website at 
