Jassin had been occupied by the British in order to secure the border between British East Africa and German territory, but was weakly defended by a garrison of four companies of Indian troops, commanded by Colonel Raghbir Singh [4][5] and numbering a little over 300 men.

[6] The German commander, Paul Emil von Lettow-Vorbeck, decided to attack Jassin in order to prevent further danger to Tanga, which lay more than 50 kilometres to the south and had previously been successfully defended against a British attack.

Brigadier-General Michael Tighe arrived too late, just hours after the surrender to support the British at Jassin.

[7] Although the British force surrendered, Lettow-Vorbeck realised that the level of German losses of officers and ammunition meant that he could rarely afford confrontation on such a large scale and would need to make use of guerrilla warfare instead—he turned his attention away from seeking decisive battle against the British, concentrating instead on operations against the Uganda Railway.

[8] The British response was to withdraw and concentrate their forces in order to reduce their risks and make defence easier.