Osiris was the first god born to live upon the earth. His brother Set was the second. It was decided (some say by Ra) that Osiris would rule lower Egypt and Set would rule upper Egypt. Lower Egypt had an abundance of fertile soil and Osiris was quite skilled at the art of growing. In fact, it is written that where ever he walked, things would bloom. He traveled throughout Egypt teaching people how to produce food from the land. Before this people were primarily hunters. This in turn helped to 'domesticate' people. That is, they were able to settle down and begin to appreciate the finer things of life, instead of constantly roaming the land in search of food. Meanwhile, Set was growing increasingly disgruntled by the popularity of his brother. Set's kingdom was for the most part barren and his people therefore relied on hunting for food. Many of his people saw what was happening in Osiris' kingdom and wished to have an easier life too. So, they began migrating north. Before long Set decided he must put an end to this. His plan was simple. He obtained the exact measurements of Osiris' body and had a chest made to fit him. Set had heard that Isis was away traveling and Osiris was having a party to celebrate his 28th birthday. Set showed up at Osiris' home with the chest and 72 companions. It was said to be a very beautiful chest, with inlaid gold and precious stones. Set declared that who ever fit inside the chest would be able to keep it. A couple of people tried it but they did not fit. Then Osiris tried it and of course it was a perfect fit. As soon as he laid down inside of it, Set's companions closed the lid and nailed it shut. They ran off with it and threw it into the Nile. When Isis got word of this she immediately began her search for the body of Osiris. She eventually found him and partially brought him back to life.

When Set discovered that Osiris had been regenerated, he once again set out to destroy his brother. He found Osiris and cut him into 14 pieces and threw them into the Nile. Isis, Nephthys and Anubis found 13 pieces and with the help of Thoth they were able to resurrect his soul.

From this point on, Osiris made his kingdom the underworld or the Duat/Tuat. Before his arrival it was a barren, desolate place. But Osiris brought the joys of life on earth to the Duat. People who practiced a good existence while on earth were assured of a pleasant afterlife with all the amenities they enjoyed while alive.