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.
He was the founder of the Greco-Bactrian Kingdom.
Diodotus and his successors were able to maintain themselves against the attacks of the Seleucids—particularly from Antiochus III the Great, who was ultimately defeated by the Romans (190 BC).

The Greco-Bactrians were so powerful that they were able to expand their territory as far as India:
As for Bactria, a part of it lies alongside Aria towards the north, though most of it lies above Aria and to the east of it.
And much of it produces everything except oil.
The Greeks who caused Bactria to revolt grew so powerful on account of the fertility of the country that they became masters, not only of Bactria and beyond, but also of India, as Apollodorus of Artemita says: and more tribes were subdued by them than by Alexander...."
The Greco-Bactrians used the Greek language for administrative purposes, and the local Bactrian language was also Hellenized, as suggested by its adoption of the Greek alphabet and Greek loanwords.
In turn, some of these words were also borrowed by modern Pashto.
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. He was the founder of the Greco-Bactrian Kingdom. Diodotus and his successors were able to maintain themselves against the attacks of the Seleucids—particularly from Antiochus III the Great, who was ultimately defeated by the Romans (190 BC).
The Greco-Bactrians were so powerful that they were able to expand their territory as far as India:
As for Bactria, a part of it lies alongside Aria towards the north, though most of it lies above Aria and to the east of it. And much of it produces everything except oil. The Greeks who caused Bactria to revolt grew so powerful on account of the fertility of the country that they became masters, not only of Bactria and beyond, but also of India, as Apollodorus of Artemita says: and more tribes were subdued by them than by Alexander...."
The Greco-Bactrians used the Greek language for administrative purposes, and the local Bactrian language was also Hellenized, as suggested by its adoption of the Greek alphabet and Greek loanwords. In turn, some of these words were also borrowed by modern Pashto.
Bactria