The next major power in the region was the Illiniwek Confederation, a political alliance among several tribes. The Illiniwek gave Illinois its name. The Ho-Chunk, a Siouan people of the Chiwere subgroup & the alleged oldest continuous Siouan society, were also believed to claim some land north of the Rock River. During the Beaver Wars period of the 17th century, the Iroquois pushed through and briefly conquered Ohio, Indiana & Southern Michigan, forcing several peoples out of those regions. Several migrating groups of Miami & Mascouten—the oldest known inhabitants of Indiana & S. Michigan—spread throughout the western Great Lakes & Upper Mississippi region, living wherever they could. The known tribes were the Miami, Mascouten, Wea, Atchatchakangouen, Pepicokia, Mengakonkia, Pinakashaw & Kilatika. The Beaver Wars also caused a secondary conflict in the greater Wisconsin area known as the Second Fauk War, which pushed the ancestors of the Lakota/ Dakota out onto the plains & destabilized the Dakotas.