Moses and his brother Aaron asked the pharaoh of Egypt to let the people of Israel leave Egypt in order to celebrate a feast in the wilderness to honor their God. The pharaoh didn't know their god and wouldn't let them off for a holiday.
God told Moses that He would demonstrate His power to convince the pharaoh. First, He would make the pharaoh more adamant against their leaving and then He would produce signs or portents, which turned out to be the 10 plagues.
When Moses and Aaron next approached the pharaoh, they produced a miracle: Aaron threw down his staff and it turned into a snake. This seemed less like a miracle from a god than magic to the Egyptians. Indeed, court sorcerers easily duplicated the feat. But then, Aaron's staff swallowed up the court sorcerers' staffs -- considerably more miraculous. Following divine orders, Moses then told the pharaoh that his rod would work a miracle. This would be the first of the 10 plagues of Egypt.
Articles that may be of interest:
- "The Plagues as Ecological Signs of Historical Disaster," by Terence E. Fretheim. Journal of Biblical Literature, Vol. 110, No. 3 (Autumn, 1991), pp. 385-396
- "Moses as They Saw Him," by S. A. Nigosian. Vetus Testamentum, Vol. 43, Fasc. 3 (Jul., 1993), pp. 339-350.
- Times Online has an article, "Plagues of Egypt 'caused by nature, not God'" about the validity of the plagues.
- What Were the 10 Plagues?
- When Was the Exodus?
- What Are the 10 Commandments?
- Who Was Saul?
- When Was the United Monarchy?
- What Was the Prophecy About Jesus in the Old Testament?