 Joining the Hitler Youth when his church scout group was absorbed into the organisation shortly after the Nazi party's rise to power in Germany in 1933, like many German young people of his generation Metelmann became an enthusiastic supporter of nazism at an early age.In 1941 at the age of 18 he joined the Wehrmacht and was posted to the Crimea with the 11th Army.As a tank driver in the 22nd Panzer Division which was virtually destroyed in 1942, he was briefly captured by Red Army soldiers and was involved in the Battle of Stalingrad.