Karol participated in the individual jumping competition at the 1912 Summer Olympics in Stockholm.
After the armistice he remained in the army as a professional soldier. He also resumed his sporting career as the main coach of the Polish equestrian national team.
During the World War II Rómmel remained in the German-occupied part of Poland. After the war he settled in Łódź, where he continued to coach younger generations of horse riders.
Career
Karol participated in numerous international games, winning World Cup three times: in 1925, 1927 (New York) and 1928 (Nice).
He won four medals at consecutive Polish Championships (gold in 1935 and 1937, silver in 1938 and bronze in 1934). In the 1927 Polish Sportspersonality of the Year he ended up second only to Halina Konopacka. Rómmel was 51 when in 1939 he set the last pre-war high jump record (198 centimeters).