Complex sentence: The battle of Kousséri originates From French plans to occupy the Chari-Baguirmi region and so, in 1899--1900, three armed expeditions were organized, one proceeding north from Congo, one east from Niger and another south from Algeria.
Split into simpler sentences: The battle of Kousséri originated in French plans to occupy the Chari-Baguirmi region. In 1899--1900, the French organized three armed columns, one proceeding north from Congo, one east from Niger and another south from Algeria.