The Illinois Confederation, sometimes referred to as the Illiniwek or Illini, were a group of 12–13 Native American tribes in the upper Mississippi River valley of North America. The tribes were the Kaskaskia, Cahokia, Peoria, Tamaroa, Moingwena, Michigamea, Chepoussa, Chinkoa, Coiracoentanon, Espeminkia, Maroa, and Tapouara. At the time of European contact in the 17th century, they were believed to number over 10,000 people. The Illinois spoke various dialects of the Miami-Illinois language, one of the Algonquian languages family. They occupied a broad inverted triangle from modern-day Iowa to near the shores of Lake Michigan in modern Chicago south to modern Arkansas. By the mid-18th century, only five principal tribes remained—the Cahokia, Kaskaskia, Michigamea, Peoria, and Tamaroa.