Ardabil is an ancient Azerbaijani city situated at an altitude of 1,570 meters above sea level, located along historic trade routes. According to Sumerian inscriptions, Ardabil has a history spanning nearly 5,000 years.
Muslim historians associate the founding of Ardabil with the Sasanian ruler King of Kings Peroz I (reigned 459–484), who named the city Firuzabad. In the early Islamic period, the Arabs maintained Ardabil's status as a political and administrative center. During the reign of Caliph Ali (656–661), the Arab governor of Azerbaijan, al-Ash'ath ibn Qays, settled Arabs in Ardabil at the expense of the state, developed the city, and built a mosque there.
During the Umayyad dynasty, Azerbaijan’s capital was moved from Maragha to Ardabil. Between 661 and 750, Ardabil served as the Arabs’ military and administrative headquarters in the region. According to D. Behazin, “Ardabil was the capital of Azerbaijan during the Sasanian and early Arab periods, and during the Abbasid period, it became the center of the Iranians’ (the author considers Azerbaijani Turks as Persians) resistance against Arab rule.”
It is believed that the name Ardabil originates from the Avestan language, derived from the word Artabil, which consists of two parts – arta and vil – meaning "holy place."
In 941, after bringing an end to the Sajid dynasty, Marzuban ibn Muhammad established the Sallarid dynasty and retained Ardabil as its capital.
Under the Safavid rule, Ardabil reached a peak in its socio-economic development and became one of the most prominent cities in the Near East.
In the 1740s, following the death of Nader Shah, Nazarali Khan Shahsevan declared himself an independent khan in Ardabil, which then became the capital of the Ardabil Khanate. In 1746, following Nader Shah's coronation in the Ultan Fortress of Mughan (Suqovuşan), the event was celebrated ceremoniously in Ardabil.
During the Qajar period, Ardabil, like other Azerbaijani cities, gradually lost its significance.
The population of Ardabil was estimated at 14–15 thousand in 1728, 20 thousand by the late 19th century, and 40 thousand by 1930. According to the 2017 census, Ardabil city had a population of 605,992, while the Ardabil region had 529,374 residents.
Historically, the vast majority (98%) of Ardabil’s population has been Azerbaijani Turks, and Azerbaijani Turkish remains the primary spoken language today.