Diyar Mudar in the context of "Balikh River"

Al-Jazira (Arabic: الجزيرة), also known as Jazirat Aqur or Iqlim Aqur, was a province of the Rashidun, Umayyad and Abbasid Caliphates, spanning at minimum most of Upper Mesopotamia (al-Jazira proper), divided between the districts of Diyar Bakr, Diyar Rabi'a and Diyar Mudar, and at times including Mosul, Arminiya and Adharbayjan as sub-provinces.

Following its conquest by the Muslim Arabs in 639/40, it became an administrative unit attached to the larger district of Jund Hims. It was separated from Hims during the reigns of caliphs Mu'awiya I or Yazid I and came under the jurisdiction of Jund Qinnasrin. It was made its own province in 692 by Caliph Abd al-Malik. After 702, it frequently came to span the key districts of Arminiya and Adharbayjan along the Caliphate's northern frontier, making it a super-province. The predominance of Arabs from the Qays/Mudar and Rabi'a groups made it a major recruitment pool of tribesmen for the Umayyad armies and the troops of the Jazira played a key military role under the Umayyad caliphs in the 8th century, peaking under the last Umayyad caliph, Marwan II (r. 744–750), until the toppling of the Umayyads by the Abbasids in 750.

Diyar Bakr (Arabic: دِيَارُ بَكرٍ, romanized: Diyār Bakr, lit. 'abode of Bakr') is the medieval Arabic name of the northernmost of the three provinces of the Jazira (Upper Mesopotamia), the other two being Diyar Mudar and Diyar Rabi'a. According to the medieval geographer al-Baladhuri, all three provinces were named after the main Arab tribes that were settled there by Mu'awiya in the course of the Muslim conquests of the 7th century. The Diyar Bakr was settled by the Rabi'a subgroup of the Banu Bakr, and hence the two provinces are sometimes referred to collectively as "Diyar Rabi'a". In later Turkish usage, "Diyar Bakr" referred to the western portion of the former province, around Amid (which hence became known as Diyarbakır in Turkish).

Diyar Bakr encompasses the region on both banks of the upper course of the river Tigris, from its sources to approximately where its course changes from a west-east to a southeasterly direction. Its main city was Amida (Amid in Arabic), and other major settlements included Mayyafariqin, Hisn Kaifa, and Arzan. Geographically and politically, in early Islamic times the Diyar Bakr was usually part of the Jazira, but it was sometimes joined to the Armenian province to the north. In the late 9th century, it was controlled by an autonomous dynasty founded by Isa ibn al-Shaykh al-Shaybani. In the mid-10th century, the region passed into the hands of the Hamdanids, but their rule was contested by the Buyids (978–983) and after that the Marwanids.

The Numayrids (Arabic: النميريون) were an Arab dynasty based in Diyar Mudar (western Upper Mesopotamia). They were emirs (princes) of their namesake tribe, the Banu Numayr. The senior branch of the dynasty, founded by Waththab ibn Sabiq in 990, ruled the Euphrates cities of Harran, Saruj and Raqqa more or less continuously until the late 11th century. In the early part of Waththab's reign (r. 990–1019), the Numayrids also controlled Edessa until the Byzantines conquered it in the early 1030s. In 1062, the Numayrids lost Raqqa to their distant kinsmen and erstwhile allies, the Mirdasids, while by 1081, their capital Harran and nearby Saruj were conquered by the Turkish Seljuks and their Arab Uqaylid allies. Numayrid emirs continued to hold isolated fortresses in Upper Mesopotamia, such as Qal'at an-Najm and Sinn Ibn Utayr near Samosata until the early 12th century, but nothing is heard of them after 1120.

As Bedouin (nomadic Arabs), most Numayrid emirs avoided settled life in the cities they controlled; rather, they ruled their emirates (principalities) from their tribal encampments in the countryside, while entrusting administration of the cities to their ghilmān (military slaves). An exception was Emir Mani' ibn Shabib (r. ca. 1044–1063), under whom the Numayrids reached their territorial peak. Mani' resided inside Harran, transforming its Sabian temple into an ornate, fortified palace. The Numayrids were Shia Muslims and initially recognized the religious sovereignty of the Sunni Muslim Abbasid Caliphate, at least nominally, but later switched allegiance to the Shia Fatimid Caliphate after the latter extended its influence into northern Syria in 1037. By 1060, they likely reverted to Abbasid suzerainty.

Diyar Rabi'a (Arabic: دِيَارُ رَبِيعَةَ, romanized: Diyār Rabīʿa, lit. 'abode of Rabi'a') is the medieval Arabic name of the easternmost and largest of the three provinces of the Jazira (Upper Mesopotamia), the other two being Diyar Bakr and Diyar Mudar. According to the medieval geographer al-Baladhuri, all three provinces were named after the main Arab tribes that were settled there by Mu'awiya in the course of the Muslim conquests of the 7th century. The Diyar Rabi'a was settled by the Rabi'a tribe.