The German campaign in Angola took place before the official declaration of war between Germany and Portugal in March 1916. German and Portuguese troops clashed several times on the border between German South West Africa and Portuguese Angola. The Germans won most of these clashes and were able to occupy the Humbe region of southern Angola until Portuguese control was restored a few days before the British campaign out of South Africa defeated the Germans.

The Kingdom of Portugal had been allied with England since 1373, and thus the Republic of Portugal was an ally of the United Kingdom. However, Portugal remained neutral from the start of World War I in 1914 until early 1916. However, in that year and a half there were many hostile engagements between Germany and Portugal. Portugal wanted to meet British requests for aid and protect its colonies in Africa, causing clashes with German troops in the south of Portuguese Angola, which bordered German South West Africa, in 1914 and 1915.