The Israelites became enslaved in Egypt and were led away by Moses. This event is called the Exodus. Jewish and Christian traditions share the telling of these events in the books of the Law. The books of Genesis and Exodus, located in the Torah and the Christian Bible, contain information about the Exodus.
According to the Biblical telling, Israelites who had settled in Egypt became enslaved. A man named Moses, who had been raised with the Pharaoh's family, led them out of Egypt. This only occurred after Moses asked the Pharaoh to let the enslaved Israelites go. When the Pharaoh refused, God sent a series of plagues. The Egyptians suffered from the plagues, which ranged from an infestation of frogs to the death of all the firstborn children. The Pharaoh eventually allowed the Israelite slaves to leave, though he sent soldiers to follow them. The Israelites managed to escape from the soldiers when God parted the waters of the Red Sea so that they could cross.
Modern scholars of history generally believe that there is evidence for some sort of Exodus, though most do not believe in the literal telling from the Bible. For example, many scholars believe that the "Red Sea" was really the Sea of Reeds, which were shallow lakes in the region.