Asadabad (, also Romanized as Asadābād) is a city and capital of Asadabad County, Hamadan Province, Iran. At the 2006 census, its population was 51,304, in 12,583 families. Asadabad is located 54 kilometers southwest of Hamadan, the provincial capital, on the historic route from Baghdad to Hamadan and then on to Ray and Tehran. The Kuh-e Alvand, the innermost part of the Zagros mountains, separates Asadabad and Hamadan. History Little is known about Asadabad's pre-Islamic history, although its strategic location suggests great antiquity. Wilhelm Tomaschek suggested a possible identification with the place named "Adrapana" by Isidore of Charax. Asadabad was an important royal site during the Sasanian period, with the 10th-century traveler Abu Dolaf Khazraji reporting that Mardanshah, son of the Sasanian ruler Khosrow II and his wife Shirin, lived here for some time. Another writer, Ibn al-Faqih, reported that the Sasanian emperors kept a palace at a nearby place called Āzarmīḏdoḵt. The most visible Sasanian ruins in medieval times was the site variously called the Maṭābeḵ Kesrā ("Kitchens of Chosroes") or the Ayvān al-Ṣanj ("Portico of the Cymbal") by medieval Muslim writers. Early Islamic Asadabad was a small but prosperous city in the province of Jebal, surrounded by fertile farmlands that produced cereals, cotton, fruit, and especially honey. These farmlands were irrigated by waters brought down from the Kuh-e Alvand via qanats. In 810-11, during the Fourth Fitna, a battle was fought at Asadabad between the forces of al-Amin and al-Ma'mun, two sons of the Abbasid caliph Harun al-Rashid. Al-Ma'mun's general Taher Dhu'l-Yaminayn, who would later go on to found the Tahirid dynasty of Khorasan, defeated al-Amin's commander Abd-al-Rahman ibn Jabala Abnawi, who was killed in battle. As a result of this battle, al-Ma'mun's forces were able to take control of the entire province of Jebal. In the early 11th century, Asadabad was contested between different factions within the Kurdish Hasanwayhid dynasty. Later, in 1023-24, the Daylamite Kakuyid ruler Mohammad ibn Rostam Doshmanziyar took control of the city. Another battle was fought at Asadabad in 1120, when Mas'ud ibn Mohammad, the governor of Mosul, al-Jazira, and Azerbaijan, unsuccessfully rebelled against the Seljuq emperor Mahmud II. Asadabad continued to thrive under Ilkhanid rule; the 14th-century writer Hamdallah Mustawfi recorded that 35 villages were dependent on Asadabad, with the total revenue of the district amounting to 15,000 dinars. It was a minor center of Islamic scholarship, with the writer al-Sam'ani listing