"Awarded for his successes as a U-Boat commander. While commanding U-23 he sunk 8 ships with 24899 GRT (including the British destroyer HMS Daring). Over the course of three more war patrols with U-99 he sunk a further 9 ships with 49704 GRT, damaged 3 with 25545 GRT, and captured 1 more with 2136 GRT." from his Knight's Cross to the Iron Cross citation, awarded on 4 August 1940.
"Awarded for sinking another 15 ships with 65654 GRT and damaging 1 more with 3106 GRT over the course of three patrols with U-99." from his Knight's Cross to the Iron Cross with Oak Leaves citation, awarded on 4 November 1940.
"Awarded for his successes on his last two war patrols with U-99. In this time he sank the British auxiliary cruiser HMS Forfar (with 16402 GRT) and another 13 ships with 79000 GRT, furthermore damaging 1 more ship with 9314 GRT." from his Knight's Cross to the Iron Cross with Oak Leaves and Swords citation, awarded on 26 December 1941.
Another deadly enemy elite,