In 1914, World War I erupted, and German East Africa became a battlefield. At the time, only 55 Germans and 450 Schutztruppe askari guarded all of Burundi. However, the Belgians in the neighbouring Congo overestimated the German strength and were hampered by poor logistics. Thus, the Allies initially refrained from attempting offensive operations into Burundi. In contrast, Langenn-Steinkeller decided to launch a raid into enemy territory without authorisation by German East Africa's chief commander, Paul von Lettow-Vorbeck. He led one of the companies under his command, namely the 5. Feldkompanie (5/FK) to capture Karonga, part of British Nyasaland. Supported by 500 Ruga-Ruga, he launched the operation unaware that strong British forces were close to Karonga, and suffered a heavy defeat. Langenn-Steinkeller's troops were decimated, and he was seriously wounded, losing the use of one eye. After this failure, he returned to Burundi for several months, before being ordered to relocate to Neu Langenburg to oversee the southwestern frontline in February 1915.
