Called "beautiful Bactria, crowned with flags" by the Avesta, the region is considered, in the Zoroastrian faith, to be one of the "sixteen perfect Iranian lands" that the supreme deity, Ahura Mazda, had created.

[1] Bactria was the centre of Iranian resistance against the Greek Macedonian invaders after the fall of the Achaemenid Empire in the 4th century BC, but eventually fell to Alexander the Great.

[citation needed] The Seleucids lost the region after the declaration of independence by the satrap of Bactria, Diodotus I; thus began the history of the Greco-Bactrian, and later the Indo-Greek, Kingdoms.

The capital city of Bactra was centre of an Iranian Renaissance in the 8th and 9th centuries,[4] and New Persian as an independent literary language first emerged in this region.

The Bactrian plain lay between the Amu Darya (ancient Oxus River) to the north and the Hindu Kush mountain range to the south and east.

Since the decipherment of cuneiform script in the 19th century, however, which enabled actual Assyrian records to be read, historians have ascribed little value to the Greek account.

Bactria was the homeland (Airyanem Vaejah) of Indo-Iranians who moved south-west into Iran and the north-west of the South Asian subcontinent around 2500–2000 BC.

[13] It was in these regions, where the fertile soil of the mountainous country is surrounded by the Turan Depression, that the prophet Zoroaster was said to have been born and gained his first adherents.

Ernst Herzfeld suggested that Bactria belonged to the Medes[14] before its annexation to the Achaemenid Empire by Cyrus the Great in sixth century BC, after which it and Margiana formed the twelfth satrapy of Persia.

[18] In addition, Xerxes also settled the "Branchidae" in Bactria; they were the descendants of Greek priests who had once lived near Didyma (western Asia Minor) and betrayed the temple to him.

In the south, beyond the Oxus, he met strong resistance, but ultimately conquered the region through both military force and diplomacy, marrying Roxana, daughter of the defeated Satrap of Bactria, Oxyartes.

After Alexander's death, Diodorus Siculus tells us that Philip received dominion over Bactria, but Justin names Amyntas to that role.

[22] When Alexander's troops entered Bactria they discovered communities of Greeks who appeared to have been deported to the region by the Persians in previous centuries.

Considerable difficulties faced by the Seleucid kings and the attacks of Pharaoh Ptolemy II Philadelphus gave the satrap of Bactria, Diodotus I, the opportunity to declare independence about 245 BC and conquer Sogdia.

[25] The Bactrian king Euthydemus I and his son Demetrius I crossed the Hindu Kush mountains and began the conquest of the Indus valley.

His successors managed to cling to power until the last known Indo-Greek ruler, a king named Strato II, who ruled in the Punjab region until around 55 BC.

The Yuezhi had conquered Bactria by the time of the visit of the Chinese envoy Zhang Qian (circa 127 BC), who had been sent by the Han emperor to investigate lands to the west of China.

[28][29] The first mention of these events in European literature appeared in the 1st century BC, when Strabo described how "the Asii, Pasiani, Tokhari, and Sakarauli" had taken part in the "destruction of the Greco-Bactrian kingdom".

Following these reports, the Chinese emperor Wu Di was informed of the level of sophistication of the urban civilizations of Ferghana, Bactria and Parthia, and became interested in developing commercial relationship with them: The Son of Heaven on hearing all this reasoned thus: Dayuan and the possessions of Daxia and Anxi Parthia are large countries, full of rare things, with a population living in fixed abodes and given to occupations somewhat identical with those of the people of Han, but with weak armies, and placing great value on the rich produce of China.

Kujula Kadphises, the xihou (prince) of the Yuezhi, united the region in the early 1st century and laid the foundations for the powerful, but short-lived, Kushan Empire.

By the mid-7th century AD, Islam under the Rashidun Caliphate had come to rule much of the Middle East and western areas of Central Asia.

The Umayyad forces captured the area around Balkh, including the Buddhist monastery at Nava Vihara, causing the Shahis to retreat to the Kabul Valley.

[34] Several important trade routes from India and China (including the Silk Road) passed through Bactria and, as early as the Bronze Age, this had allowed the accumulation of vast amounts of wealth by the mostly nomadic population.

The Encyclopaedia Iranica states:Bactrian thus occupies an intermediary position between Pashto and Yidgha-Munji on the one hand, Sogdian, Choresmian, and Parthian on the other: it is thus in its natural and rightful place in Bactria.

[40][41][42] The Encyclopædia Britannica states:The Tajiks are the direct descendants of the Iranian peoples whose continuous presence in Central Asia and northern Afghanistan is attested from the middle of the 1st millennium BC.

The ancestors of the Tajiks constituted the core of the ancient population of Khwārezm (Khorezm) and Bactria, which formed part of Transoxania (Sogdiana).