Joseph LaFlesche, also known as E-sta-mah-za or Iron Eye (1822–1888), was the last recognized head chief of the Omaha tribe of Native Americans who was selected according to the traditional tribal rituals. The head chief Big Elk had adopted LaFlesche as an adult into the Omaha and designated him in 1843 as his successor. LaFlesche was of Ponca and French Canadian ancestry; he became a chief in 1853, after Big Elk's death. An 1889 account said that he had been the only chief among the Omaha to have known European ancestry.