East Azerbaijan Province is one of the 31 provinces of Iran. It is located in Iranian Azerbaijan, bordering with Armenia, Republic of Azerbaijan, Ardabil Province, West Azerbaijan Province, and Zanjan Province. The capital of East Azerbaijan is Tabriz. East Azerbaijan Province is in Regions 3 of Iran, with its secretariat located in its capital city, Tabriz.
The oldest kingdom known in Iranian Azerbaijan is that of the Mannea who ruled a region southeast of Lake Urmia centered around modern Saqqez. The Manneans were a confederation of Iranian and non-Iranian groups. According to Professor Zadok:
it is unlikely that there was any ethnolinguistic unity in Mannea. Like other peoples of the Iranian plateau, the Manneans were subjected to an ever increasing Iranian (i.e., Indo-European) penetration.
The Mannaeans were conquered and absorbed by an Iranian people called Matieni, and the country was called Matiene, with Lake Urmia called Lake Matianus. Matiene was later conquered by the Medes and became a satrapy of the Median empire and then a sub-satrapy of the Median satrapy of the Persian Empire.
According to Encyclopædia Britannica, the Medes were an:
Indo-European people, related to the Persians, who entered northeastern Iran probably as early as the 17th century BC and settled in the plateau land that came to be known as Media.
After Alexander the Great conquered Persia, he appointed (328 BC) as governor the Persian general Atropates, who eventually established an independent dynasty. The region, which came to be known as Atropatene or Media Atropatene (after Atropates), was much disputed. In the 2nd century BC, it was liberated from Seleucid domination by Mithradates I of Arsacid dynasty, and was later made a province of the Sassanid Empire of Ardashir I. Under the Sassanids, Azerbaijan was ruled by a marzubān, and, towards the end of the period, belonged to the family of Farrokh Hormizd. Heraclius, the Byzantine emperor, briefly held the region in the 7th century until peace was made with the Sassanids. After the Islamic Conquest of Iran, Arab invaders converted most of its people to Islam and made it part of the caliphate.