Pharaoh oppressed the Israelites because he feared that they might become too numerous and join his enemies to fight him. According to the book of Exodus in the Bible, the Israelites had settled in Egypt during a time of famine and had become prosperous. This worried the new Pharaoh, who did not remember Joseph or the Israelites' contribution to Egypt's prosperity. To control their population, he ordered them to be enslaved and worked them harshly. He also ordered the midwives to kill all male infants at birth, but they defied him, and the Israelites continued to grow in number. This led to further oppression and eventually, the Exodus, where God delivered the Israelites from slavery in Egypt.