World War I started on July 28, 1914 and ended November 11, 1918. The total number of participating personnel is estimated by the Encyclopedia Britannica at 65,038,810 and there were 9,750,103 military deaths during the conflict.
The oldest verified World War I veteran is 109 year old Frank Buckles, born February 1, 1901. World War I veteran Emiliano Mercado del Toro of Puerto Rico, August 21, 1891 - January 24, 2007, who died at age 115 was the oldest authenticated veteran from any conflict to have ever lived. On May 27, 2008, the last Central Powers veteran Franz Kunstler of Austria-Hungary, died at the age of 107.