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, in present-day Tanzania, and were running critically low on supplies. To remedy the problem, the Germans invaded Portuguese East Africa to the south in an attempt to escape superior British forces to the north and resupply themselves with captured Portuguese materiel. Portugal was part of the Entente and a belligerent, employing troops in France. A Portuguese force under the command of Major João Teixeira Pinto was sent to stop von Lettow-Vorbeck from crossing the border, but was flanked by the Germans while encamped at Ngomano on 25 November 1917. The resulting battle saw the Portuguese force nearly destroyed, with many troops killed and captured. The capitulation of the Portuguese force enabled the Germans to seize a large quantity of supplies, thereby allowing von Lettow-Vorbeck to continue his operations in East Africa until the end of the war.

• http://en.wikipedia.org/wiki/Battle of Ngomano