MOHAMMERAH, a town and port of South-west Persia situated in Lat. 3o° 25' Long. 48° 1o' on the right bank of the Karun river (q.v.) at the point where it enters the Shatt al Arab (q.v.). Until the beginning of the 19th century the old village of the same name lay on the left bank of the Karun on the island of Abadan (q.v.) opposite the present town.
The place first came into prominence in 1837, when it was at tacked and demolished by the Turks on the ground that it was becoming a thriving commercial port to the detriment of Basra. Persia claimed an indemnity of one million pounds sterling: the Turks on the other hand claimed that both Mohammerah and Abadan were Turkish territory. The British and Russian Gov ernments intervened to prevent war and by the Treaty of Erzerum (1847), Mohammerah and its anchorage, and Abadan island were allocated to Persia. One of the principal difficulties in effecting this settlement was the fact that in 1765 the Karun, which had hitherto entered the Persian Gulf by a separate chan nel via Marid, Qubban and the Khor Musa, left that channel and followed a small canal which had been dug to connect Marid with Mohammerah by the Bahmishir, then a branch of the Shatt al Arab, thus depriving Persia of the advantages of independent access to the Persian gulf. On the inclusion of Mohammerah and district in Persian territory they were constituted, adminis tratively, a deputy-governorship under the provincial Governor of Arabistan (Khuzistan) with headquarters at Shushter ; but in practice they were farmed out, or delegated to the ruling Shaikh of the Muhaisin section of the Chaab, the Shia tribe of Arabs inhabiting the region. Sir Khazaal Khan G.C.I.E., K.C.S.I.,
the present titular Shaikh, has always maintained most cordial relations with British representatives in the Persian gulf and Mesopotamia. A British vice-consulate has been established at Mohammerah since 1891.
During the Anglo-Persian War of 1857 the town was assaulted and taken by the British force under Sir James Outram and occupied until the conclusion of peace.
Mohammerah is connected by river with Ahwaz (105 m.) ; good motor roads connect the town with Ahwaz (8o m.), Basra (25 m.), Abadan (9 m.). It is in telephonic communication via Ahwaz with the rest of Persia, but not with Basra owing (1928) to diplomatic difficulties.
The only local product of importance is dates, which are ex ported in considerable quantities from the date-groves which line the Shatt al Arab and Bahmishir rivers. It is, however, a port of considerable importance, its imports averaging for the past three years over' one million pounds sterling; exports about £200,000: representing respectively about 45,000 and 22,000 tons. 146 ships entered the port in 1925-6 of which 141 were British. The average rainfall at Mohammerah is 8 in. per annum, as com pared with about double that amount at Masjid, Sulaiman, 120 miles north. The climate is hot but not unhealthy.