Hamedan, also spelled HAMADAN, ancient Ecbatana, city, west-central Iran, at the northeastern foot of Mount Alvand (11,716 feet [3,571 m]). Itself at an elevation of 6,158 feet (1,877 m), the city dominates the wide, fertile plain of the upper Qareh-Su River. There is a sizable Turkish-speaking minority. The city, although certainly an older foundation, has records only from the 1st millennium BC.

Hamadan has had many names: it was possibly the Bit Daiukki of the Assyrians, Hegbatana, or Agbatana, to the Medes, and Ecbatana to the Greeks. One of the Median capitals, under Cyrus II the Great (d. 529 BC) and later Achaemenid rulers, it was the site of a royal summer palace. A little east of Hamadan is the Mossala, a natural mound the debris of which includes the remains of ancient Ecbatana, which has never been excavated. The modern city is built partly on its mounds. The city is mentioned in the Bible (Ezra 6:2).The city was captured by the Arabs in 641 or 642 and for some centuries remained a provincial capital, though important only commercially.  In the second half of the 12th century, the Seljuq Turkish sultans made it their capital, and so it remained for 50 years. To this period dates the building of Gonbad-e 'Alaviyan, a mausoleum with fine stucco work. About 1220 Hamadan was destroyed by the Mongols; in 1386 it was sacked by Tamerlane, a Turkic conqueror, and the inhabitants massacred. It was partly restored in the 17th century and subsequently changed hands often between Iranian ruling houses and the Ottomans. In modern times its strategic position has caused a revival. The city was damaged during the Iran-Iraq War of the 1980s. Modern development is modest.

In summer the pleasant climate makes Hamadan a resort, but the winters are long and severe. Hamadan is an important trade centre on the main Tehran-Baghdad highway. 
Capital of the province of Hamadan, ancient Ecbatana, the Medes’ capital. It was the residence of Achaemenian Kings, and the summer resort of the Parthian and Sassanian dynasties. In the 7 century AD, Hamadan passed to the Arabs, and it was later held by the Seljuk Turks
(12th-13th centuries) and the Mongols (13th- 14th centuries)
Hamadan’s climate is mild and delightful in summers, and cold in winters. 
The ruins of ancient Hagmatana, on the site of which the present Hamadan stands, date from the period of Median monarchs (7 and early 6 centuries BC) who had made that city their capital.