His reign was characterized by the infiltration and surprise attack near his Kigali hill palace by the army of King Cwamali of Bunyoro in Uganda.
Kigeli I, together with his son Sekarongoro I, staged a defensive battle against Cwamali's army around what is modern-day Kigali city.
[3] Sekarongoro I Mutabazi sustained an injury to his forehead, bleeding, which lead the Rwandan army to retreat.
The Bunyoro army suffered numerous casualties and a great defeat, with some captured as prisoners of war.
The Banyoro captives had their fingers and toes mutilated and sent back to Bunyoro as a message to instill fear into King Cwamali.