Which island off the east coast of Africa was once independent?

thanks for your amazing and informative comments.

my sister An Irish Diplomat. she is going to Dar Es Salaam the Capital of Tanzania 🇹🇿 from August of 2025. I want to do a safari and going to Zanzibar

Since the gain of Independence in Tanzania the island of Zanzibar and Pemba has joined the mainland and has become one country.