In 1902 he graduated from Vilnius Military Academy. Larka participated in the Russo-Japanese War and graduated from the Imperial Nicholas Military Academy in 1912. He participated in World War I fighting on the Eastern front against the German Empire, including fighting in East Prussia, Poland and Romania. Larka became the first Minister of War of Republic of Estonia; in March he achieved rank of Major General. In 1918, during the German occupation, he participated in organising the Defence League. After the start of the Estonian Liberation War in 1918, Larka soon moved from position of Minister of War to Chief of Staff. In February 1919 he became the aide of the Minister of War and held that position to the beginning of 1925. In that position his job was to organize mobilization and actio