as a consequence of an 1804 treaty between the governor of indiana territory and a group of sauk and fox leaders regarding land settlement, the sauk and fox tribes vacated their lands in illinois and moved west of the mississippi in 1828. however, sauk chief black hawk and others disputed the treaty, claiming that the full tribal councils had not been consulted, nor did those representing the tribes have authorization to cede lands. angered by the loss of his birthplace, between 1830–31 black hawk led a number of incursions across the mississippi river, but was persuaded to return west each time without bloodshed. in april 1832, encouraged by promises of alliance with other tribes and the british, he again moved his so-called "british band" of around 1000 warriors and non-combatants into illinois. finding no allies, he attempted to return across the mississippi (to modern iowa), but ensuing events led to the battle of stillman's run. a number of other engagements followed and the militia of michigan territory and the state of illinois were mobilized to hunt down black hawk's band. the conflict became known as the black hawk war. after stillman's run, an ambush at buffalo grove killed one militia member two days before the raid on the plum river settlement.