Numbers 22:7

22:7 So the elders of Moab and the elders of Midian departed with the fee for divination in their hand. They came to Balaam and reported to him the words of Balak.

Numbers 31:8

31:8 They killed the kings of Midian in addition to those slain – Evi, Rekem, Zur, Hur, and Reba – five Midianite kings. They also killed Balaam son of Beor with the sword.