Tuekakas, commonly known as Old Chief Joseph or Joseph the Elder, was a Native American leader of the Wallowa Band of the Nez Perce. Old Joseph was one of the first Nez Percé converts to Christianity and a vigorous advocate of the tribe's early peace with whites. In 1855 he aided Washington's territorial governor and set up a Nez Percé reservation that expanded from Oregon into Idaho. The Nez Perce agreed to give up a section of their tribal lands in return for an assurance whites would not intrude upon the sacred Wallowa Valley.