In the sixth century BCE a city stood at the head of the Punjab plain where the roads from Central Asia come down out of the hills. Its Sanskrit name was Takṣaśilā; the Greeks wrote it Taxila. It became the north-west's meeting point of trade, government and study, and it is where the tradition places the education of Pāṇini, whose grammar of Sanskrit is the most rigorous description of a language produced anywhere before the modern era.
The place
Taxila lies in Rawalpindi District, Punjab province, Pakistan, and has been a UNESCO World Heritage Site since 1980. The site is not one city but a sequence of them: the Bhir Mound, the earliest, from roughly the sixth to the second century BCE; Sirkap, laid out on a grid by the Indo-Greeks; Sirsukh, built under the Kushans. This article concerns the first of the three, when the region lay under Achaemenid Persian overlordship and the north-west was the subcontinent's doorway to the Iranian world.
What kind of place it was
Buddhist Jataka stories describe students travelling long distances to Taxila to study under named teachers. Later tradition places the statecraft theorist Kauṭilya and the physician Jīvaka there. This is literary evidence of reputation, written down generations after the events it describes.
Pāṇini
Tradition places his birth at Salātura in Gandhara — usually identified with a site near Lahur in modern Khyber Pakhtunkhwa, outside Punjab's present boundary though within the same cultural region and close to Taxila, which lies inside it. Pāṇini belongs to the ancient north-west; Punjab holds that world's intellectual centre. That is the accurate claim, and we make it rather than the larger one.
His dates are not settled. Estimates run from the sixth to the fourth century BCE, with most current scholarship favouring the fifth to fourth. The dating is Under discussion; that the text is the coherent work of a single mind is Well-established.
The Aṣṭādhyāyī
The name means “eight chapters.” It consists of roughly four thousand sūtras — rules compressed to the point of being nearly unreadable without a commentary tradition, which duly grew up around it. It operates through a metalanguage of its own devising: abbreviation symbols that stand for classes of sounds, technical markers attached to elements to control how rules apply, an ordering principle under which a later rule overrides an earlier one, and recursion. Twentieth-century linguists recognised in it structures their own discipline reached only in the twentieth century, and it is now routinely compared to a formal generative grammar. The linguist Leonard Bloomfield described it as one of the great monuments of human intelligence.
Two features are easy to miss and worth stating. Pāṇini cites earlier grammarians by name, so he stands at the end of a developed tradition rather than at its start. And he is describing a language that people were speaking — the Aṣṭādhyāyī analyses a living tongue, and includes notes on regional and optional usages.
Consequences
By fixing Sanskrit's form so exactly, Pāṇini's work became the standard against which the language was transmitted for two thousand years — one reason Sanskrit changed so little over so long. The commentarial tradition that followed him, particularly Patañjali's Mahābhāṣya, became a discipline in its own right.
Long-term significance for Punjab
This entry establishes something the rest of the ancient timeline can easily obscure: the north-west was not only a frontier that empires marched across. It was a place where some of the subcontinent's intellectual instruments were made, and where the region's oldest habits — literacy in more than one script, trade in more than one direction — were already in place before Alexander arrived. It also fixes Sanskrit, the language of the Rigveda, into the form in which it was carried down the centuries.
Modern place-names
Taxila, Rawalpindi District, Punjab, Pakistan. Salatura → near Lahur, Swabi District, Khyber Pakhtunkhwa, Pakistan.