Crowfoot (c. 1830 – 25 April 1890) or Isapo-Muxika (Blackfoot Issapóómahksika, "Crow-big-foot) was a chief of the Siksika First Nation. His parents, Istowun-eh'pata (Packs a Knife) and Axkahp-say-pi (Attacked Towards Home), were Kainai. His brother Iron Shield became Chief Bull. He was only five when Istowun-eh'pata was killed during a raid on the Crow tribe, and a year later, his mother remarried to Akay-nehka-simi (Many Names) of the Siksika people. The young boy was adopted by the Siksika, who gave him the name Kyi-i-staah (Bear Ghost), until he could receive his father’s name, Istowun-eh’pata.
While a young man, he was included in horse raid on a Crow encampment. Because of his brave performance and injury during the battle, he was finally given his adult name, Isapo-muxika, taken from a deceased relative.
Crowfoot was a warrior who fought in as many as nineteen battles and sustained many injuries. Despite this, he tried to obtain peace instead of tribal warfare. When the Canadian Pacific Railway sought to build their mainline through Blackfoot territory, negotiations with Father Lacombe convinced Crowfoot that it should be allowed.
In 1877 Colonel James Macleod and Lieutenant-Governor David Liard drew up Treaty Number 7 and persuaded Crowfoot and other chiefs to sign it. Canadian Pacific Railway President William Van Horne gave Crowfoot a lifetime pass to ride on the CPR out of gratitude.
Though he was well respected for his bravery, Crowfoot refused to join the North-West Rebellion of 1885, believing it to be a lost cause. In 1886, Prime Minister Sir John A. Macdonald invited Crowfoot to Ottawa. Crowfoot went, as did Three Bulls and Red Crow, but soon fell ill and had to return from Ottawa.