Greater Tunb is one of two rocky islands belonging to the United Arab Emirates that lie close to the Straits of Hormuz, at the mouth of the Arabian Gulf. It was invaded by Iran in November 1971, and remains under Iranian occupation. The UAE has offered to hold bilateral talks on ownership of the island or to submit the issue to international arbitration, but Iran has refused.
The island was an important outpost of the maritime empire of the Qasimi family, based in Ras al-Khaimah, who ruled it for nearly 300 years prior to the Iranian occupation.
One of the earliest written descriptions comes from a British marine survey in the Gulf in the 1820s: "The Great Tomb [Greater Tunb] is a level island about three miles (5 kilometres) long and two and a half broad (4 kilometres), on it are a few trees, it may be seen from a frigate's deck five leagues...water is to be obtained from a well near a banyan tree some distance from the beach at the western end".
No archaeological survey has been conducted on the island, although with water present, it is likely to have been regularly visited by mariners over a long period. Reports of wildlife include the only nesting record of barn swallow for the UAE. The lighthouse on Greater Tunb is said to have housed breeding pairs of this species annually prior to 1927. White-cheeked terns also nested in some numbers, while it is likely a number of other seabird species would also have been present.
A small fishing community, whose members were forcibly expelled in 1971 and now live in Ras al-Khaimah, formerly occupied the island.