Early History of Pakistan

Main articles: Achaemenid Empire, Maurya Empire, Greco-Bactrian Kingdom, and Indo-Greek kingdom
See also: Kushan Empire, Indo-Scythians, Indo-Parthian Kingdom, Gupta Empire, and Rai Dynasty
The Indus plains formed the most populous and richest satrapy of the Persian Achaemenid Empire for almost two centuries, starting from the reign of Darius the Great (522-485 BCE).[22] Its heritage influenced the region e. g. adoption of Aramaic script, which the Achaemenids used for the Persian language; but after the end of Achaemenid rule, other scripts became more popular, such as Kharoṣṭhī (derived from Aramaic) and Greek. The interaction between Hellenistic Greece and Buddhism began when Alexander the Great overthrew the Achaemenid empire in 334 BCE, and marched eastwards. Eventually, after defeating King Porus in the fierce Battle of the Hydaspes (near modern Jhelum), he conquered much of the Punjab region. But, his battle weary troops refused to advance further into India[23] to engage the formidable army of Nanda Dynasty and its vanguard of trampling elephants, new monstorities to the invaders. Therefore, Alexander proceeded southwest along the Indus valley.[24] Along the way, he engaged in several battles with smaller kingdoms before marching his army westward across the Makran desert towards modern Iran. Alexander founded several new Macedonian/Greek settlements in Gandhara and Punjab.

The region that is now Pakistan was for much of its history part of various Persian dynasties, such as the Achaemenid dynasty of the Persian Empire (559–330 BCE)
Chandragupta Maurya, a fugitive general from Magadha empire of the Nandas, who later raised his own military force and ultimately overthrew the Nanda Dynasty - using Macedonian tactics - and founded the Mauryan dynasty in Magadha, that lasted about 180 years.[25] After Alexander's death in 323BCE, his Diadochi (generals) divided the empire, with Seleucus setting up the Seleucid Kingdom, which included the Indus plain.[26] Chandragupta Maurya took advantage of this fragmentation of Greek power and captured the Punjab and Gandhara.[27] Later, the eastern part of the Seleucid Kingdom broke away to form the Greco-Bactrian Kingdom (third–second century BCE). Chandragupta's grandson, Ashoka the Great, (273-232 BCE) expanded the Mauryan empire to its greatest extent covering most of South Asia. He converted to Buddhism after feeling remorse for his bloody conquest of Kalinga in eastern India. His Edicts were written on pillars in Aramaic (the lingua franca of the Achaemenid Empire) or in Kharoṣṭhī.[28]
Greco-Buddhism (or Græco-Buddhism) was the syncretism between the culture of Classical Greece and Buddhism in the area of modern Afghanistan and Pakistan, between the fourth century BCE and the fifth century CE.[29] It influenced the artistic development of Buddhism, and in particular Mahayana Buddhism, before it spread to central and eastern Asia, from the 1st century CE onward. Demetrius (son of the Greco-Bactrian king Euthydemus) invaded northern India in 180 BCE as far as Pataliputra and established an Indo-Greek kingdom. To the south, the Greeks captured Sindh and nearby coastal areas, completing the invasion by 175 BCE and confining the Sungas to the east. Meanwhile, in Bactria, the usurper Eucratides killed Demetrius in a battle. Although the Indo-Greeks lost part of the Gangetic plain, their kingdom lasted nearly two centuries.
The Indo-Greek Menander I (reigned 155-130 BCE) drove the Greco-Bactrians out of Gandhara and beyond the Hindu Kush, becoming a king shortly after his victory. His territories covered Panjshir and Kapisa in modern Afghanistan and extended to the Punjab region, with many tributaries to the south and east, possibly as far as Mathura. The capital Sagala (modern Sialkot) prospered greatly under Menander's rule and Menander is one of the few Bactrian kings mentioned by Greek authors.[30] The classical Buddhist text Milinda Pañha, praises Menander, saying there was "none equal to Milinda in all India".[31] His empire survived him in a fragmented manner until the last independent Greek king, Strato II, disappeared around 10 CE. Around 125 BCE, the Greco-Bactrian king Heliocles, son of Eucratides, fled from the Yuezhi invasion of Bactria and relocated to Gandhara, pushing the Indo-Greeks east of the Jhelum River. Various petty kings ruled into the early first century CE, until the conquests by the Scythians, Parthians and the Yuezhi, who founded the Kushan dynasty. The last known Indo-Greek ruler was Theodamas, from the Bajaur area of Gandhara, mentioned on a 1st century CE signet ring, bearing the Kharoṣṭhī inscription "Su Theodamasa" ("Su" was the Greek transliteration of the Kushan royal title "Shau" ("Shah" or "King")).
The Indo-Scythians were descended from the Sakas (Scythians) who migrated from southern Siberia to Kashmir and Arachosia from the middle of the 2nd century BCE to the 1st century BCE. They displaced the Indo-Greeks and ruled a kingdom that stretched from Gandhara to Mathura and Scythian tribes spread further into northwest India and the Iranian plateau.
The Parni were a nomadic Central Asian tribe who overthrew the Persian Seleucids and annexed much of the Indus region. Following the decline of the central Parthian authority after clashes with the Roman Empire, a local Parthian leader, Gondophares established the Indo-Parthian Kingdom in the 1st century CE. The kingdom was ruled from Taxila and covered much of modern southeast Afghanistan, Pakistan and northwestern India.[32]