muḥāfaẓah (governorate) in the middle Nile River delta, Lower Egypt. It is bounded to the east and west by the Damietta and the Rosetta branches of the Nile, to the north by Kafr al-Shaykh governorate, and by Al-Minūfīyah governorate to the south. The governorate's capital has been at the cultural centre and transportation node of Ṭanṭā since 1836. An administrative unit named Al-Gharbīyah has existed since the early Muslim period. It formerly included the entire central delta north to the Mediterranean, but in 1949 Fuʾādīyah mudīrīyah (province), named for former king Fuʾād I, was created out of the northern part of Al-Gharbīyah. Renamed in 1955, after the overthrow of the monarchy (1952), it is now the governorate of Kafr al-Shaykh. Southern Al-Gharbīyah has an extremely high population density.

The fertile, flat land of the governorate has a network of irrigation canals and is a cotton-growing centre. Rice, grains, and fruit are also grown. A barrage at Ziftā raises the level of the Damietta Branch to supply irrigation canals within the area and to the north and east. Important market towns with industries largely based on agriculture are Ziftā, Basyūn, and Ṭanṭā; Al-Maḥallah al-Kubrā is a major textile centre. Kafr al-Zayyāt on the right bank of the Rosetta Branch has one of the country's largest cotton ginneries as well as soap and chemical works. In the governorate's northwestern section, on the right bank of the Rosetta and north of the village of Ṣā al-Ḥajar, is ancient Sais. The railway from Cairo splits at Ṭanṭā, with the western branch going to Alexandria and the eastern to Damietta; branches off the main lines serve towns in the governorate. Pop. (2004 est.) 3,859,378.