Andronovo culture in the context of "Khakas"

Tajikistan, officially the Republic of Tajikistan, is a landlocked country in Central Asia. Dushanbe is its capital and most populous city. Tajikistan borders Afghanistan to the south, Uzbekistan to the west, Kyrgyzstan to the north, and China to the east and is narrowly separated from Pakistan by Afghanistan's Wakhan Corridor. It has a population of more than 10.7 million people.

The territory was previously home to cultures of the Neolithic and the Bronze Age, including the Oxus civilisation in west, with the Indo-Iranians arriving during the Andronovo culture. Parts of country were part of the Sogdian and Bactrian civilisations, and was ruled by those including the Achaemenids, Alexander the Great, the Greco-Bactrians, the Kushans, the Kidarites and Hephthalites, the First Turkic Khaganate, the Umayyad and Abbasid Caliphates, the Samanid Empire, the Kara-Khanids, Seljuks, Khwarazmians, the Mongols, Timurids and Khanate of Bukhara. The region was later conquered by the Russian Empire, before becoming part of the Soviet Union. Within the Soviet Union, the country's borders were drawn when it was part of Uzbekistan as an autonomous republic before becoming a constituent republic of the Soviet Union on 5 December 1929.

Proto-Iranian or Proto-Iranic is the reconstructed proto-language of the Iranian languages branch of Indo-European language family and thus the ancestor of the Iranian languages such as Persian, Pashto, Sogdian, Zazaki, Ossetian, Mazandarani, Kurdish, Talysh and others. Its speakers, the hypothetical Proto-Iranians, are assumed to have lived in the 2nd millennium BC and are usually connected with the Andronovo archaeological horizon (see Indo-Iranians).

Proto-Iranian was a satem language descended from the Proto-Indo-Iranian language, which in turn, came from the Proto-Indo-European language. It was likely removed less than a millennium from the Avestan language, and less than two millennia from Proto-Indo-European.

The Indo-Iranian peoples, or Indo-Iranic peoples, also known as Ā́rya or Aryans from their self-designation, were a group of speakers of Indo-European languages who brought the offshoot Indo-Iranian languages to parts of Eurasia in waves from the first part of the 2nd millennium BC onwards. They eventually branched out into the Iranian peoples and Indo-Aryan peoples.

The historical Vedic religion, also called Vedism or Brahmanism, and sometimes ancient Hinduism or Vedic Hinduism, constituted the religious ideas and practices prevalent amongst some of the Indo-Aryan peoples of the northwest Indian subcontinent (Punjab and the western Ganges plain) during the Vedic period (c. 1500–500 BCE). These ideas and practices are found in the Vedic texts, and some Vedic rituals are still practised today. The Vedic religion is one of the major traditions which shaped modern Hinduism, though present-day Hinduism is significantly different from the historical Vedic religion.

The Vedic religion has roots in the Indo-Iranian culture and religion of the Sintashta (c. 2200–1750 BCE) and Andronovo (c. 2000–1150 BCE) cultures of Eurasian Steppe. This Indo-Iranian religion borrowed "distinctive religious beliefs and practices" from the non-Indo-Aryan Bactria–Margiana culture (BMAC; 2250–1700 BCE) of south of Central Asia, when pastoral Indo-Aryan tribes stayed there as a separate people in the early 2nd millennium BCE. From the BMAC Indo-Aryan tribes migrated to the northwestern region of the Indian subcontinent, and the Vedic religion developed there during the early Vedic period (c. 1500–1100 BCE) as a variant of Indo-Aryan religion, influenced by the remnants of the late Indus Valley Civilisation (2600–1900 BCE).

The Kurgan hypothesis (also known as the Kurgan theory, Kurgan model, or steppe theory) is the most widely accepted proposal to identify the Proto-Indo-European homeland from which the Indo-European languages spread out throughout Europe and parts of Asia. It postulates that the people of a Kurgan culture in the Pontic steppe north of the Black Sea were the most likely speakers of the Proto-Indo-European language (PIE). The term is derived from the Turkic word kurgan (курга́н), meaning tumulus or burial mound.

The steppe theory was first formulated by Otto Schrader (1883) and V. Gordon Childe (1926), then systematized in the 1950s by Marija Gimbutas, who used the term to group various prehistoric cultures, including the Yamnaya (or Pit Grave) culture and its predecessors. In the 2000s, David Anthony instead used the core Yamnaya culture and its relationship with other cultures as a point of reference.

The Bactria–Margiana Archaeological Complex (BMAC) is the modern archaeological designation for a particular Middle Bronze Age civilisation of southern Central Asia, also known as the Oxus Civilization. The civilisation's urban phase or Integration Era was dated in 2010 by Sandro Salvatori to c. 2400–1950 BC, but a different view is held by Nadezhda A. Dubova and Bertille Lyonnet, c. 2250–1700 BC.

Though it may be called the "Oxus civilization", apparently centred on the upper Amu Darya (Oxus River) in Bactria, most of the BMAC's urban sites are located in Margiana (now Turkmenistan) on the Marghab delta, and in the Kopet Dagh range. There are a few later (c. 1950–1450 BC) sites in northern Bactria, today southern Uzbekistan, but they are mostly graveyards belonging to the BMAC-related Sapalli culture. A single BMAC site, known as Dashli, lies in southern Bactria, current territory of northern Afghanistan. Sites found further east, in southwestern Tajikistan, though contemporary with the main BMAC sites in Margiana, are only graveyards, with no urban developments associated with them.