Sindh, also spelled Sind, province of southeastern Pakistan. It is bordered by the provinces of Balochistān on the west and north, Punjab on the northeast, the Indian states of Rajasthan and Gujarat to the east, and the Arabian Sea to the south. Sindh is essentially part of the Indus River delta and has derived its name from that river, which is known in Pakistan as the Sindhu. The province of Sindh was established in 1970. The provincial capital, Karāchi, is situated on the southwestern coast. Area 54,407 square miles (140,914 square km). Pop. (2006 est.) 35,864,000.
The area of present-day Sindh province was the centre of the ancient Indus valley civilization, as represented by the sites of Mohenjo-daro, Amre, and Kot Diji. This early civilization existed from about 2300 to 1750 BCE. There is then a gap of more than a millennium before the historical record is renewed with Sindh’s annexation to the (Persian) Achaemenid empire under Darius I in the late 6th century BCE. Nearly two centuries later, Alexander the Great conquered the region in 326 and 325 BCE. After his death, Sindh came under the domination of the empires of Seleucus I Nicator, Chandragupta Maurya (c. 305 BCE), the Indo-Greeks and Parthians in the 3rd–2nd century BCE, and the Scythians and the Kushāns from about 100 BCE to 200 CE. Sindh’s population adopted Buddhism under the Kushān rulers in the 1st century CE. From the 3rd to the 7th century CE, the area remained under the rule of the Persian Sāsānids. The Arab conquest of Sindh in 711 heralded the entry of Islam into the Indian subcontinent. Sindh was part of the administrative province of Al-Sind in the Umayyad and ʿAbbāsid empires from 712 to about 900, with its capital at Al-Manṣūrah, 45 miles (72 km) north of present-day Hyderabad. With the eventual weakening of central authority in the caliphate, the Arab governors of Al-Sindh established their own dynastic rule of the region from the 10th to the 16th century. In the 16th and 17th centuries Sindh was ruled by the Mughals (1591–1700) and then by several independent Sindhian dynasties, the last of which lost the region to the British in 1843. At that time most of Sindh was annexed to the Bombay Presidency. In 1937 Sindh was established as a separate province in British India, but after Pakistani independence it was integrated into the province of West Pakistan from 1955 to 1970, at which time it was reestablished as a separate province.