Jephthah (Personal name meaning "he will open." One of Israel's judges about 1100 B.C. (Judges 11:1-12:7). A Gileadite, he was driven from his home because he was "the son of a harlot" (Judges 11:1). He lived & raided in the land of Tob with a band of outlaws, becoming known as a "mighty warrior." When the Ammonites moved against Israel, Jephthah people asked him to return & lead them. His victory over the Ammonites came about after a vow he made to offer as a burnt offering the first living thing he saw upon his return from battle. Although it was his daughter who greeted him, Jephthah did fulfill his rash vow. Considering as one of Yahweh's "chief" deliverers of His people (1 Samuel 12:11), Jephthah is hailed by the author of Hebrews, as a hero of faith (Hebrews 11:32).
For further study of the lesson "Google" Ammon; Ammonites; Human Sacrifices; Book of Judges.
Reference summary used from the Holman Illustrated Bible Dictionary, @2003 by Holman Bible Publishers; Nashville, TN