Context : Heinz Strüning (13 January 1912 -- 24 December 1944) was a German Luftwaffe fighter ace and recipient of the Knight's Cross of the Iron Cross with Oak Leaves (German: Ritterkreuz des Eisernen Kreuzes mit Eichenlaub) during World War II. The Knight's Cross of the Iron Cross and its higher grade Oak Leaves was awarded to recognise extreme battlefield bravery or successful military leadership. 
Answer : Knight's Cross of the Iron Cross with Oak Leaves
Which award was honoured to Heinz Strüning?