Tajikistan gained independence in 1991, and has experienced three changes in government and a civil war since then. A peace agreement among rival factions was signed in 1997 but its implementation has progressed slowly.
Pre-Islamic Period (600 BC–AD 651)
Tajikistan was part of the Bactria-Margiana Archaeological Complex in the Bronze Age, candidate for Proto-Indo-Iranian or Proto-Iranian culture. Tajikistan was part of Scythia in Classical Antiquity.
Most of modern Tajikstan had formed parts of ancient Kamboja and Parama Kamboja kingdoms, which find references in the ancient Indian epics like the Mahabharata. Linguistic evidence, combined with ancient literary and inscriptional evidence has led many eminent Indologists to conclude that ancient Kambojas (an Avestan speaking Iranain tribe) originally belonged to the Ghalcha-speaking area of Central Asia. Achariya Yasaka's Nirukta  (7th c BCE) attests that verb Śavati in the sense "to go" was used by only the Kambojas. It has been shown that the modern Ghalcha dialects, Valkhi, Shigali, Sriqoli, Jebaka (also called Sanglichi or Ishkashim), Munjani, Yidga and Yagnobi, mainly spoken in Pamirs and countries on the headwaters of the Oxus, still use terms derived from ancient Kamboja Śavati in the sense "to go" . The Yagnobi dialect spoken in Yagnobi province around the headwaters of Zeravshan valley in Sogdiana, also still contains a relic "Śu" from ancient Kamboja Śavati in the sense "to go" . Further, Sir G Grierson says that the speech of Badakshan was a Ghalcha till about three centuries ago when it was supplanted by a form of Persian . Thus, the ancient Kamboja, probably included the Badakshan, Pamirs and northern territories including Yagnobi province in the doab of the Oxus and Jaxartes . On the east it was bounded roughly by Yarkand and/or Kashgar, on the west by Bahlika (Uttaramadra), on the northwest by Sogdiana, on the north by Uttarakuru, on the southeast by Darada, and on the south by Gandhara. Numerous Indologists locate original Kamboja in Pamirs and Badakshan and the Parama Kamboja further north, in the Trans-Pamirian territories comprising Zeravshan valley, north up parts of Sogdhiana/Fargana--in the Sakadvipa or Scythia of the classical writers . Thus, in the pre-Buddhist times (7th/6th c BCE), the parts of modern Tajikstan including territories as far as Zeravshan valley in Sogdiana formed parts of ancient Kamboja and the Parama Kamboja kingdoms when it was ruled by Iranian Kambojas till it became part of Achaemenid Empire.
Sogdiana, Bactria, Merv and Khorezm were the four principal divisions of Ancient Central Asia inhabited by the ancestors of the present-day Tajiks. Tajiks are now found only in historic Bactria and Sogdiana. Merv is inhabited by the Turkoman and Khorezm by Karakalpaks, Uzbeks and Kazakhs. The Sogdians were famous for being tall, massive, and of a fair colour, possibly resembling the Scythians. Among them Bactria and Khorezm were kingdoms during different period of history unlike Sogdiana and Merv which were geographical locations and vassals of different kingdoms. Sogdiana was made up of the Zeravshan and Kashka-Darya river valleys. Currently, One of the surviving peoples of Sogdiana who speak a dialect of the Sogdian language are the Yaghnobis and Shugnanis who live in the Northern region of Tajikistan around the Zeravshan valley. Bactria was located in northern Afghanistan (present-day Afghan Turkestan) between the mountain range of the Hindu Kush and the Amu Darya (Oxus) River and some areas of current...