Bactria is an ancient region of Central Asia, between the Hindu Kush Mountain range and the Oxus River (today generally called the Amu Darya River). In more recent times, the region also goes by the name "Balkh," after one of the tributary rivers of the Amu Darya.
Historically often a unified region, Bactria now is divided among many Central Asian nations: Turkmenistan, Afghanistan, Uzbekistan, and Tajikistan, plus a sliver of what is now Pakistan. Two of its significant cities that are still important today are Samarkhand (in Uzbekistan) and Kunduz (in northern Afghanistan).
Brief History of Bactria:
Archaeological evidence and early Greek accounts indicate that the area east of Persia and northwest of India has been home to organized empires since at least 2,500 BCE, and possibly much longer. The great philosopher Zoroaster, or Zarathustra, is said to have come from Bactria. Scholars have long debated when the historical personage of Zoroaster lived, with some proponents claiming a date as early as 10,000 BCE, but this is all speculative. In any event, his beliefs form the basis for Zoroastrianism, which strongly influenced the later monotheistic religions of southwest Asia (Judaism, Christianity and Islam).
In the sixth century BCE, Cyrus the Great conquered Bactria and added it to the Persian or Achaemenid Empire. When Darius III fell to Alexander the Great in the Battle of Gaugamela (Arbela), in 331 BCE, Bactria was thrown into chaos. Due to strong local resistance, it took the Greek army two years to put down the Bactrian insurgency, but their power was tenuous at best.
Alexander the Great died in 323 BCE, and Bactria became part of his general Seleucus's satrapy. Seleucus and his descendants governed the Seleucid Empire in Persia and Bactria until 255 BCE. At that time, the satrap Diodotus declared independence and founded the Greco-Bactrian Kingdom, which covered the area south of the Caspian Sea, up to the Aral Sea, and east to the Hindu Kush and Pamir Mountains. This large empire did not last long, however, being conquered first by the Scythians (around 125 BCE) and then by the Kushans (Yuezhi).
The Kushan Empire itself lasted only from the 1st to 3rd centuries CE, but under the Kushan emperors its power spread from Bactria into the whole of northern India. At this time, Buddhist beliefs mingled with the earlier amalgam of Zoroastrian and Hellenistic relgious practices common in the area. Another name for the Kushan-controlled Bactria was "Tokharistan," because the Indo-European Yuezhi were also called the Tocharians.
The Sassanid Empire of Persia under Ardashir I conquered Bactria from the Kushans around 225 CE, and ruled the area until 651. In succession, the area was conquered by the Turks, Arabs, Mongols, Timurids, and eventually, in the eighteenth and nineteenth centuries, Tsarist Russia.
Because of its key position astride the overland Silk Road, and as a central hub between the great imperial areas of China, India, Persia and the Mediterranean world, Bactria has long been prone to conquest and contestation. Today, what was once called Bactria forms much of "the 'Stans," and is once more valued for its reserves of oil and natural gas, as well as for its potential as an ally of either moderate Islam or Islamic fundamentalism. In other words, watch out for Bactria - it has never been a quiet region!