Persian Gulf at its narrowest, in the Strait of Hormuz. The waters are overall very shallow, with a maximum depth of and an average depth of . Countries with a coastline on the Persian Gulf are (clockwise, from the north): Iran; Oman's Musandam exclave; the United Arab Emirates; Saudi Arabia Qatar, on a peninsula off the Saudi coast; Bahrain, on an island; Kuwait; and Iraq in the northwest. Various small islands also lie within the Persian Gulf, some of which are the subject of territorial disputes between the states of the region. The International Hydrographic Organization defines the Persian Gulf's southern limit
Persian Gulf BC, the southern part of the Persian Gulf was dominated by the Dilmun civilization. For a long time the most important settlement on the southern coast of the Persian Gulf was Gerrha. In the 2nd century the Lakhum tribe, who lived in what is now Yemen, migrated north and founded the Lakhmid Kingdom along the southern coast. Occasional ancient battles took place along the Persian Gulf coastlines, between the Sassanid Persian empire and the Lakhmid Kingdom, the most prominent of which was the invasion led by Shapur II against the Lakhmids, leading to Lakhmids' defeat, and advancement into Arabia, along