 The united expeditions, now under the overall command of Lamy, returned south to Joalland's base camp on the right bank of the Chari River, near where it enters Lake Chad from the south.The joint expedition conquered Kousséri in April 1900; shortly afterwards, on April 21, they were joined by a third expedition, the Gentil Mission, that had entered the area from the Congo and been awaiting them for some time in the region of Lake Chad.The following day, in the battle of Kousséri, this combined force totally defeated Rabih az-Zubayr's forces, and Rabih was killed in the fight, his empire crumbling with him.