Turkowski was born on 28 July 1894 in the village of Iwkowa, which at that time belonged to Austrian Galicia. He attended a high school in nearby Bochnia, after which studied law at Jagiellonian University in Kraków. In 1914, Turkowski joined Polish Legions Second (then Third) Infantry Regiment. Wounded in the Battle of Kostiuchnówka (July 1916), he was captured by the Russians. Released in 1917, Turkowski joined Polish II Corps in Russia. Promoted to lieutenant, he fought in the Battle of Kaniów.