mauss took part in operation barbarossa, the invasion of the soviet union in june 1941. in november 1941, he was awarded the knight's cross of the iron cross. in 1942 mauss was promoted to colonel; he was awarded the oak leaves to the knight's cross in november, 1943. in january 1944 he took command of the 7th panzer division. on 23 october 1944 he received the knight's cross with oak leaves and swords. in february 1945 he was seriously injured and had a leg amputated. he was promoted to lieutenant general in april, and received the knight's cross with oak leaves, swords, and diamonds on 15 april 1945.