Occurrence of Attributes in Original Text

The text related to the cultural heritage 'Stone Town of Zanzibar' has mentioned 'Protectorate' in the following places:
Occurrence Sentence Text Source
Former capital of the Zanzibar Sultanate, and flourishing centre of the spice trade as well as the slave trade in the 19th century, it retained its importance as the main city of Zanzibar during the period of the British protectorate.
In 1890, with the Heligoland-Zanzibar Treaty, Zanzibar itself became a British protectorate.