Osage Chief Arthur Bonnicastle was born on February 20, 1877, in Osage County, Oklahoma. He was born to a woman named Me-Tse-He. Bonnicastle spent his childhood years in Osage County. His name, Arthur Bonnicastle, was taken from a novel written by J.G. Holland called Arthur Bonnicastle: An American Novel. In 1899, Bonnicastle left Osage County and began school at the infamous Carlisle Indian Industrial School. He left Carlisle in February in 1900 to join the army.
Upon enlisting in the army Bonnicastle was assigned to the 9th U.S. Cavalry, where he worked his way up to the rank of Sergeant. In 1900 the 9th Cavalry was dispatched to China to aid with the growing hostilities of the Boxer Rebellion. Bonnicastle participated in the Battle of Tientsin and the Battle of Yangcun. The rebellion came to an end in 1901, and Bonnicastle returned stateside shortly after. In 1903 he was honorably discharged.
After his discharge in 1903 Bonnicastle returned to Carlisle, but stayed only a short while before returning to Osage County. In 1908 he began his political career when he ran for a seat on the Osage Tribal Council and won. When his term expired in 1910 he was not reelected. In 1920 Arthur Bonnicastle was elected to be the 8th Principal Chief of the Osage Tribe. Chief Bonnicastle served one term from 1920 to 1922. In 1922 he did not seek reelection for the office of Principal Chief, instead running for a Council seat again. Chief Bonnicastle was successful in his bid for the Council seat, and took office in 1922. Sadly Chief Bonnicastle did not finish out his term. He died in 1923, when he fell off of a train while returning home from Washington D.C. The death was ruled an accident and never investigated. But many still find the circumstances surrounding his death to be quite mysterious.