High Quality Content by WIKIPEDIA articles! The Battle of Ngomano was fought between the German Empire and Portugal during the East African Campaign of World War I. A force of Germans and Askaris under Paul Emil von Lettow-Vorbeck had just won a costly victory against the British at the Battle of Mahiwa and were running critically low on supplies. To remedy the problem the Germans invaded Portuguese East Africa in an attempt to escape superior British forces to the north and resupply from captured Portuguese materiel.