Who was Abimelech in the Bible?

Abimelech was a biblical figure who is best known for his role as a judge and king of Gerar in the Book of Judges. He was the son of Gideon and an unnamed concubine from Shechem. He had 70 half-brothers, all of whom were sons of Gideon and his many wives. Abimelech's main life event was his attempt to become king of Shechem. He convinced the citizens of Shechem to make him their king and then proceeded to kill all of his 70 half-brothers, except for Jotham, who escaped. He then reigned as king for three years before being killed in battle by a woman who dropped a millstone on his head. Abimelech is best known for his role as a judge and king of Gerar. He is also remembered for his attempt to become king of Shechem and his subsequent death. He is a cautionary tale of the dangers of ambition and power.

first mention in the bible is in the book of Genesis, chapter 20, verse 2.