of ethnic groups consisting of the Indo-Aryan, Iranian and Nuristani peoples; that is, speakers of Indo-Iranian languages. The Proto-Indo-Iranians are commonly identified with the Andronovo culture, that flourished c. 2000–1450 BCE in an area of the Eurasian Steppe that borders the Ural River on the west, the Tian Shan on the east. The older Sintashta culture (2050–1900), formerly included within the Andronovo culture, is now considered separately, but regarded as its predecessor, and accepted as part of the wider Andronovo horizon. The Indo-Aryan migration was part of the Indo-Iranian migrations from the Andronovo culture into Anatolia, Iran and South Asia. Sintashta-Petrovka culture The Sintashta culture, also known as the Sintashta-Petrovka culture or Sintashta-Arkaim culture, is a Bronze Age archaeological culture of the northern Eurasian Steppe on the borders of Eastern Europe and Central Asia, dated to the period 2050–1900 BCE. The Sintashta culture is probably the archaeological manifestation of the Indo-Iranian language group. The Sintashta culture emerged from the interaction of two antecedent cultures. Its immediate predecessor in the Ural-Tobol steppe was the Poltavka culture, an offshoot of the cattle-herding Yamnaya horizon that moved east into the region between 2800 and 2600 BCE. Several Sintashta towns were built over older Poltovka settlements or close to Poltovka cemeteries, and Poltovka motifs are common on Sintashta pottery. Sintashta material culture also shows the influence of the late Abashevo culture, a collection of Corded Ware settlements in the forest steppe zone north of the Sintashta region that were also predominantly pastoralist. Allentoft et al. (2015) also found close autosomal genetic relationship between peoples of Corded Ware culture and Sintashta culture. The earliest known chariots have been found in Sintashta burials, and the culture is considered a strong candidate for the origin of the technology, which spread throughout the Old World and played an important role in ancient warfare. Sintashta settlements are also remarkable for the intensity of copper mining and bronze metallurgy carried out there, which is unusual for a steppe culture. Because of the difficulty of identifying the remains of Sintashta sites beneath those of later settlements, the culture was only recently distinguished from the Andronovo culture. It is now recognised as a separate entity forming part of the 'Andronovo horizon'. Andronovo culture The Andronovo culture is a collection of similar local Bronze Age Indo-Iranian cultures that flourished 2000–1450 BC in western Siberia and the central Eurasian Steppe. It is probably better