By the mid 1700s, the 12 or 13 tribes of the Confederation had dwindled to five: the Cahokia, Kaskaskia, Michigamea, Peoria, and Tamaroa. European diseases drastically reduced the numbers of the Illinois. The wars had arisen due to the conflicts between tribes for resources and trade goods, or were initiated by European explorers looking to expand their land. The remaining descendants of the Illinois Confederation have merged with the Peoria and are known as the Peoria Tribe of Indians and reside in Ottawa County, Oklahoma.