The history of Khyber Pakhtunkhwa stretches back to Greek exploration in the 500s BCE. It is now a province of Pakistan in the mountainous Hindu Kush region where the South Asian subcontinent meets with Central asia.
During the colonial period, the province was the North-West Frontier Province (1901–1955), forming the northwestern frontier of British India. The government of Pakistan changed its name.
In ancient times, the region was part the state of Gandhara occupied the Vale of Peshawar and adjoining areas. This kingdom was important because of its strategic location at the eastern end of the Khyber Pass. Gandhara was annexed by the Persian Achaemenian dynasty in the early 6th century BCE and remained a Persian satrapy until 327 bce. The region then passed successively under Greek, Indian, Indo-Bactrian, Sakan, Parthian, and Kushan rule. At some point after 516 BCE, Darius Hystaspes sent Scylax, a Greek seaman from Karyanda, to explore the course of the river. Darius Hystaspes subsequently subdued the races dwelling west of the Indus and north of Kabul.
Gandhara, the modern District of Peshawar, was incorporated into a Persian satrapy, and the Assakenoi, with the tribes farther north on the Indus, formed a special satrapy, that of the Indians. Both satrapies sent troops for Xerxes' invasion of Greece in 480 BCE.
In the spring of 327 BC Alexander the Great crossed the Indian Caucasus (Hindu Kush) and advanced to Nicaea, where Omphis, king of Taxila and other chiefs joined him. Alexander then dispatched part of his force through the valley of the Kabul River, while he himself advanced into Bajaur and Swat with his light troops.