Hamadan is a city in western-central Iran situated at the base of Mount Alvand, part of a sub-range of the Zagros Mountains. The city and fertile plain surrounding it have been inhabited since remote antiquity. The site first enters into historical sources in Assyrian texts dating to the second millennium B.C.E. It became an important center under the Medes and then the Achaeminids, who captured the city in 550 B.C.E. and made it into one of their summer capitals thanks to its cool summer climate. The Greek historian Polybius described Hamadan as a prosperous, walled city when he passed through it at the beginning of the second century B.C.E.1  In late antiquity, the city had a Christian and Jewish population, and an ancient tomb popularly believed to be the burial place of Esther and Mordecai still stands close to the city center.

The city became part of the early Muslim empire in 644/24 AH. At this time, it remained an important regional center but had little impact on the wider Islamic world. In the first half of the 12th/6th century AH, however, a branch of the Seljuk Dynasty made Hamadan their capital, and the town rose in prominence and flourished for a brief period. This period came to a close a century later, when the Mongols sacked the city first in 1221/618 AH and again in 1224/621 AH. Hamadan subsequently became part of the Ilkhanid, Timurid, and Safavid Empires. Its location near the western border of the Safavid Empire meant that it was prone to frontier attacks, and the Ottoman governor of Baghdad captured the city in 1724/1136 and occupied it for a period of several years after. Through these various political turns of events of the early modern period, Hamadan lost a great deal of its residents. The city's architecture also suffered, and by the nineteenth century, only a few ancient buildings remained.

Hamadan's contemporary urban design, implemented by German city planners, is of some interest. Six broad arterial avenues named after historical figures converge on a central roundabout with a green space in the middle. This maydan forms the heart of the city and is surrounded by the older quarters, including the Bazaar, whose ancient street systems remain somewhat intact. Among Hamadan's other modern urban features are the tombs of two of its important literary-historical figures: the tomb of Ibn Sina (Avicenna), a famous philosopher and scholar of medicine who died in Hamadan; and Baba Tahir, a mystical poet.

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Sources: 

Aḏkā'i, Parviz. “HAMADĀN vi. HISTORY, ISLAMIC PERIOD.” Encyclopædia Iranica, XI/6, pp. 608-612.  http://www.iranicaonline.org/articles/hamadan-vi (Accessed December 30, 2012).

Eshragh, Abdolhamid. “HAMADĀN iv. URBAN PLAN.” Encyclopædia Iranica, XI/6, pp. 607-608. http://www.iranicaonline.org/articles/hamadan-iv (Accessed on December 30, 2012).

Hausleiter, A., M. Roaf, E.J. Keall, Jeffrey Becker, DARMC, Francis Deblauwe, Tom Elliott, Sean Gillies, Eric Kansa, Brady Kiesling, H. Kopp, W. Röllig, B. Siewert-Mayer, R. Talbert, and Johan Åhlfeldt. "Ecbatana/ Hagmatana/ Achmeta/ Epiphaneia/ Ahmadan: a Pleiades place resource." Pleiades: A Gazetteer of Past Places, 2018. https://pleiades.stoa.org/places/903021 (Accessed July 2, 2018).