When Europeans arrived in the region in the late 17th century, the center of Illinois territory was situated along the Illinois River in what since has become the state of Illinois, as well as in present-day southern Wisconsin. Some bands also lived to the west of the Mississippi River in what now is eastern Iowa and Missouri and northeastern Arkansas.
The French Jesuit priests Louis Jolliet and Jacques Marquette had contacts with the Illinois in the 1670s. Father Claude Jean Allouez lived among them for several years. Henri Tonti, the lieutenant of Rene-Robert Cavelier de La Salle, established a trade relationship with them in 1680. La Salle himself visited them in 1682. The Illinois were important to the French because they controlled a stretch of the Mississippi River, the trading lane to Louisiana.
Also during the 1680s, the Illinois suffered attacks from the IROQUOIS (haudenosaunee), who invaded from the east. But the failure of the Iroquois to take Fort St. Louis on the Illinois River marked the end of the Iroquois League’s westward expansion.
Yet in the following century, the Illinois were defeated by an alliance of other tribes. For many years, the Illinois had been intermittent enemies of the Great Lakes Algon-quians as well as of the SIOUX (DAKOTA, LAKOTA, NAKOTA). As allies of the French against the British in the colonial struggle for North America (the French and Indian wars, from 1689 to 1763), however, they maintained an uneasy truce with these other tribes, who also backed the French. Some Illinois warriors even fought under the Ottawa leader Pontiac in his rebellion against the British in 1763. Yet when an Illinois Indian, supposedly in the pay of the British, killed Pontiac in 1769, many tribes—OTTAWA, CHIPPEWA (OJIBWAY), POTAWATOMI, SAC, MESKWAKI (FOX), and KICKAPOO—united against the Illinois. Many bands from these tribes came to support the British in the American Revolution. The fact that the Illinois threw their support to the Americans further incensed other tribes.
Attacks against the Illinois were relentless, and the Illinois did not have the numbers to resist them. With the Illinois’s defeat, many other Indians migrated south onto their lands. Supposedly, by the end of this conflict, the population of the Illinois had fallen from 1,800 to 150. The few survivors took refuge at the French settlement of Kaskaskia, where the Kaskaskia River meets the Mississippi in Illinois.