Emperor Karl I of Austria, also known as Charles I, reigned from 1916 to 1918 during the final years of World War I. He was born on August 17, 1887, and became the last emperor of the Austro-Hungarian Empire. His reign was marked by efforts to negotiate peace during the war and to address the growing nationalistic tensions within his empire. After the war, Karl I was forced to abdicate in 1918, leading to the dissolution of the Austro-Hungarian Empire. He went into exile in Switzerland and later attempted to regain the throne in Hungary but was unsuccessful. He died on April 1, 1922, in Madeira, Portugal.