The Qarmatians were a militant Isma'ili Shia movement centred in al-Hasa in Eastern Arabia, where they established a religious—and, as some scholars have claimed, proto-socialist or utopian socialist—state in 899 CE. Its members were part of a movement that adhered to a syncretic branch of Sevener Ismaili Shia Islam, and were ruled by a dynasty founded by Abu Sa'id al-Jannabi, a Persian from Jannaba in coastal Fars. They rejected the claim of Fatimid Caliph Abdallah al-Mahdi Billah to imamate and clung to their belief in the coming of the Mahdi, and they revolted against the Fatimid and Abbasid Caliphates.

Al-Ahsa Oasis, also known as al-Ḥasāʾ (الْحَسَاء) or Hajar (هَجَر), is an oasis and historical region in eastern Saudi Arabia. Al-Ahsa Governorate, which makes up much of the country's Eastern Province, is named after it. The oasis is located about 60 km (37 mi) inland from the coast of the Persian Gulf. Al-Ahsa Oasis comprises four main cities and 22 villages. The cities include Al-Mubarraz and Al-Hofuf, two of the largest cities in Saudi Arabia.