(July 1, 1890), arrangement between Great Britain and Germany that defined their respective spheres of influence in eastern Africa and established German control of Helgoland, a North Sea island held by the British since 1814. The treaty was symptomatic of Germany's desire for a rapprochement with Great Britain after the abandonment of a Bismarckian entente with Russia.

The treaty provided for Germany's cession to Great Britain of its claims to the Zanzibar protectorate and to the eastern African coast between Witu and the Juba River; for Great Britain's acknowledgment of a German sphere of influence on the eastern African mainland, with a northern boundary extending from Lake Victoria to the Congo state and a southwestern boundary extending from Lake Nyasa to Lake Tanganyika; for British assent to Germany's acquiring the Caprivi Strip, a narrow strip belonging to present-day Namibia, north of what is now Botswana, which gave German South West Africa access to the Zambezi River; and for the British cession to Germany of the island of Helgoland in the North Sea—a prerequisite to German naval development.