Sawad

Sawad was the name used in early Islamic times (7th–12th centuries) for southern Iraq. It means "black land" or "arable land" and refers to the stark contrast between the alluvial plain of Mesopotamia and the Arabian Desert. Under the Umayyad and Abbasid Caliphates, it was an official political term for a province encompassing most of modern Iraq except for the Syrian Desert and Upper Mesopotamia in the north. As a generic term in Arabic, sawād (سواد) was used to denote the irrigated and cultivated areas in any district. Unmodified, it always referred to southern Iraq, the sawād of Baghdad. It replaced the earlier and more narrow term Rādhān. The term sawad eventually came to refer to the rural district around a particular city; thus, contemporary geographers made references to the Sawad of Baghdad, of Basra, of Kufa, of Wasit, of Samarra, or of Anbar. This usage was exclusive to Iraq. The enormous economic potential of the Sawad is reflected in early Abbasid revenue lists: the Sawad produced four times as much tax revenue as the second-highest-producing province, Egypt, and five times as much as Syria and Palestine combined. During the medieval period, the lower Tigris followed a different course than it does today. It had shifted further west due to the floods of the early 7th century (before this, its course was the same as it is today). It passed the city of Wasit and entered the Batihah at the town of Qatr. According to Donald Hill, after about 1200, the Tigris and Euphrates started to gradually shift toward their present courses, which they finally reached during the 1500s. On the other hand, Stephen Hemsley Longrigg described the shift as taking place in the period between 1500 and 1650. In Sasanian times, the Euphrates likely entered the swamps close to the site of the modern town of Shinafiya. The Batihah (plural: Bata'ih) or great swamp was the medieval name for the vast marshlands of southern Iraq, along the lower courses of the Tigris and Euphrates.