Judges 9:5-6
9:5 He went to his father’s home in Ophrah and murdered his half-brothers, the seventy legitimate sons of Jerub-Baal, on one stone. Only Jotham, Jerub-Baal’s youngest son, escaped, because he hid.
9:6 All the leaders of Shechem and Beth Millo assembled and then went and made Abimelech king by the oak near the pillar in Shechem.