Wacław Król graduated from the Polish Air Force Academy of Dęblin in 1935 and joined the Polish Air Forces. A deputy commander of the Polish 121st Fighter Escadrille, he scored his first aerial victory on the very first day of World War II (a Henschel Hs 126, shared with Cpl Paweł Kowala). During the Nazi and Soviet invasion of Poland he downed one additional Heinkel He 111 bomber. After September 17 he escaped with his unit to Romania. Interned there, he managed to escape and reach France, where he re-joined the Polish Air Forces. Temporarily attached to the French Groupe de Chasse II/7, he took part in the Battle of France. During the German invasion of that country he scored two enemy bombers (Heinkel He 111 and Dornier Do 17) and a probable kill of another Do 17.