He was interested in the practice of medicine and was a medical student in Marburg. His reputation became one of a quiet, good natured, dutiful young man.
When war broke out in August 1914 he joined Field Regiment 62 before being posted to Field Regiment 20 following initial training, thereafter serving in Poland (out of which he was awarded the Iron Cross 2nd Class in March 1915). Allmenroder was awarded his commission at the end of March 1915.
Along with his brother Willi, Karl applied for a transfer to the Air Service a year later in March 1916; both were successful and were consequently sent for training at Halberstadt, followed by a posting to FA227 and then on to Jasta 11 in November that year.
|Allmenröder on the left|
Those 30 aerial victories were scored in the period from mid-February to the end of June 1917, including four 'kills' scored in just two days (24-25 May).
|Allmenröder at #2|
Allmenröder's brief (if spectacularly successful) aerial career came to an end on 27 June 1917 - the day following his 30th and final victory, all achieved with Jasta 11. Flying on patrol in the skies above Zillebeke his aircraft came under fire from Allied aircraft: he was killed when his 'plane crash-landed. He was aged 21 at his death.
Among Allmenröder’s awards were: the Iron Cross 1st Class in March, the Knight's Cross of the Hohenzollern Order, and - most prestigiously - the Pour le Merite in June.