efore eternal. But a great Bactrian empire certainly never existed; the
Bactrians and their neighbours were in old times ruled by petty local
kings, one of whom was Vishtaspa, the protector of Zoroaster. Ctesias in
his history of the Assyrian empire (Diodor. Sic. ii. 6 ff.) narrates a war
waged by Ninus and Semiram, against the king of Bactria (whom some later
authors, _e.g._ Justin i. 1, call Zoroaster). But the whole Assyrian
history of Ctesias is nothing but a fantastic fiction; from the Assyrian
inscriptions we know that the Assyrians never entered the eastern parts of
Iran.

Whether Bactria formed part of the Median empire, we do not know; but it
was subjugated by Cyrus and from then formed one of the satrapies of the
Persian empire. When Alexander had defeated Darius III., his murderer
Bessus, the satrap of Bactria, tried to organize a national resistance in
the east. But Bactria was conquered by Alexander without much difficulty;
it was only farther in the north, beyond the Oxus, in Sogdiana, that he met
with strong resistance. Bactria became a province of the Macedonian empire,
and soon came under the rule of Seleucus, king of Asia (see SELEUCID
DYNASTY and HELLENISM). The Macedonians (and especially Seleucus I. and his
son Antiochus I.) founded a great many Greek towns in eastern Iran, and the
Greek language became for some time dominant there. The many difficulties
against which the Seleucid kings had to fight and the attacks of Ptolemy
II., gave to Diodotus, satrap of Bactria, the opportunity of making himself
independent (about 255 B.C.) and of conquering Sogdiana. He was the founder
of the Graeco-Bactrian kingdom. Diodotus and his successors were able to
maintain themselves against the attacks of the Seleucids; and when
Antiochus III., "the Great," had been defeated by the Romans (190 B.C.),
the Bactrian king Euthydemus and his son Demetrius crossed the Hindu Kush
and began the conquest of eastern Iran and the Indus valley. For a short
time they wielded great power; a great Greek empire seemed to have arisen
far in the East. But this empire was torn by internal dissensions and
continual usurpations. When Demetrius advanced far into India one of his
generals, Eucratides, made himself king of Bactria, and soon in every
province there arose new usurpers, who proclaimed themselves kings and
fought one against the other. Most of them we know only by their coins, a
great many of which are found in Afghanistan and I