Detail of a pre-WWI map showing Perim and the Bab-el-Mandeb Peninsula. The thick doted line, that starts at Husn Murad, is the boundary line demarcating Ottoman Yemen on the west from the Aden Protectorate (British) on the east that was agreed upon by the Anglo-Ottoman Boundary Commission in 1904. The mainland facing Perim was therefore Turkish and the British launched a attack on the Turkish fort of Turba in late 1914 soon after war was declared between Britain and Turkey.