Midian was the fourth son of Abraham by his second wife, Keturah.
Abraham married Keturah some time after Sarah, his first wife, had died.
Elsewhere, Keturah was described as “Abraham’s concubine” (see 1 Chronicles 1:32).
Before Abraham died, he sent Midian and his brothers away from him. Just as he had done with Hagar and Ishmael years before, Abraham wanted to put some distance between Isaac and his half brothers. In keeping with the covenant God had made, Abraham could have but one true heir, and that was Isaac.
So Abraham gave Midian and his brothers unspecified gifts and sent them to a land east of Canaan. In that eastern land—probably Arabia—Midian’s offspring grew into a nation. His descendants would have intermittent contact with the Israelites for centuries to come—sometimes for good, sometimes for evil.
Moses’ father in-law, Jethro, was a Midianite priest who worshipped God. Despite their estrangement from the chosen family, at least some of Midian’s descendants seem to have followed in the faith of Abraham.
Later, however, the Midianites played the foil to Israel’s story. Together with the Moabites, they tried to curse the Israelites on their way into the Promised Land. They also invaded Israelite territory during the time of the judges. The enmity between Israel and Midian can be seen in passages like this: “Do to them as you did to Midian…. May they ever be ashamed and dismayed; may they perish in disgrace” (Psalm 83:9, 17).
The Midianites also played a brief but important part in the story of Joseph and his brothers (see Genesis 37). The brothers sold Joseph to a caravan of Midianite merchants, who took him to Egypt, where they in turn sold Joseph as a slave.