 It is these Hehe who in 1857 attacked the Sangu and forced them to abandon their capital of Utengule at least three times.The Sangu people repeatedly attempted to return to Utengule but failed.They retreated westwards into Usafwa, finally forcing the Wasafwa to build a new Utengule near present day Mbeya which was to become one of East Africa's most elaborate Bomas (A massive stone fortress, supposedly the largest in East Africa, later deliberately destroyed by the Germans.)