Great Britain transferred control of the islands to Germany in 1890 (Heligoland-Zanzibar Treaty) in exchange for obtaining a free hand in Zanzibar. Under the rule of the German Empire, the island became a naval base. During World War I, the island's population was evacuated to mainland Germany. The first naval battle of this war took place in the vicinity of the island in August 1914 (the Battle of Heligoland). In 1918 the population returned to the island.
Diameter 39 mm, weight 22.92 g
