https://www.btstories.com/jephthahs-vow/
Jephthah’s mother was a prostitute, but his father was a prominent man in Israel. Jephthah was raised in his father’s house, but when his half-brothers were old enough they said, “Get out! You’re not a son of our mother, and you’re not going to inherit anything from our father.”
So Jephthah left the area. He became a great warrior and organized a gang of thugs.