Merv, formerly Achaemenid Satrapy of Margiana, and later Alexandria and Antiochia in Margiana, was a major oasis-city in Central Asia, on the historical Silk Road, located near today's Mary in Turkmenistan. Several cities have existed on this site, which is significant for the interchange of culture and politics at a site of major strategic value. It is claimed that Merv was briefly the largest city in the World in the 12th century. The site of ancient Merv has been listed by UNESCO as a World Heritage Site.
Merv's origins are prehistoric: archaeological surveys have revealed many survivals of village life as far back as the 3rd millennium BC. Under the name of Mouru, Merv is mentioned with Bakhdi in the geography of the Zend-Avesta (commentaries on the Avesta). Under the Achaemenid dynasty Merv is mentioned as being a place of some importance: under the name of Margu it occurs as part of one of the satrapies in the Behistun inscriptions (ca 515 BC) of the Persian monarch Darius Hystaspis. The ancient city appears to have been re-founded by Cyrus the Great (559–530 BC), but the Achaemenid levels are deeply covered by later strata at the site.
Some exploratory excavations at Merv were conducted in 1885 by the Russian general A.V. Komarov, the governor of the Transcaspian oblast, 1883–89; Komarov employed his Tsarist troops as excavators and published his collection of trophy artifacts and coins from the area in 1900. The first fully professional dig was directed by Valentin Alekseevich Zhukovsky of the Imperial Archaeological Commission, in 1890 and published in 1894. The American Carnegie Institute's excavations were under the direction of a geologist, Raphael Pumpelly, and a German archaeologist, Hubert Schmidt.
The foundation of Gäwürgala (Turkmen take from Persian "Gabr Qala" ("Fortress of the Zoroastrians") occurred in the early Hellenistic era under the rule of the Seleucid king Antiochus I. The city was continuously inhabited under a series of Hellenistic rulers, by the Parthians, and subsequently under the Sassanids, who made it the capital of a satrapy. Gäwürgala was the capital of the Umayyad province of Khurasan and grew in importance as Khurasan became the most loyally Muslim part of the Iranian world during Islam's first two centuries.
Soltangala (from Sultan Qala," the sultan's fortress) is by far the largest of Merv's cities. Textual sources (Herrmann 1999) establish that it was Abu Muslim, the leader of the Abbasid rebellion, who symbolized the beginning of the new Caliphate by commissioning monumental structures to the west of the Gäwürgala walls, in what then became Soltangala. The area was quickly walled and became the core of medieval Merv; centuries of prosperity which followed are attested to by the many Abbasid-era köshks discovered in and outside of Soltangala.
Kushks (Persian, Kushk, "pavilion", "kiosk"), which comprise the chief remains of Abbasid Merv, are a building type unique to Central Asia during this period. A kind of semi-fortified two-story palace whose corrugated walls give it a unique and striking appearance, köshks were the residences of Merv's elite.
The oasis of Merv is situated on the Murghab River that flows down from Afghanistan, on the southern edge of the Karakum Desert, about 230 miles (370 km) north of Herat, and 280 miles (450 km) south of Khiva. Its area is about 1,900 square miles (4,900 sq km). The great chain of mountains which, under the names of Paropamisade and Hindu Kush, extends from the Caspian Sea to the Pamir Mountains is interrupted some 180 miles (290 km) south of Merv.
Through or near this gap flow northwards in parallel courses the Tejen and Murgab rivers, until they lose themselves in the Karakum Desert. Thus they make Merv a sort of watch tower over the entrance into Afghanistan on the north-west and at the same time create a stepping-stone or étape between north-east Persia and the states of Bokhara and Samarkand.
Merv is dry and hot in summer and cold in winter. The heat of summer is oppressive. The wind raises clouds of fine dust which fill the air, rendering it opaque, almost obscuring the noonday sun. These clouds make breathing difficult. In winter the climate is pleasant. Snow falls rarely, and when it does, it melts at once. The annual rainfall rarely exceeds 5 in., and there is often no rain from June until October. While in summer temperatures can reach 45 °C (113 °F), in winter it they can be as low as −7 °C (19 °F). The average yearly temperature is 16 °C (61 °F).