During his excavations in the 1950s, Mortimer Wheeler based his chronology of the Bala Hisar on the basis that iron objects had been present from the earliest levels of occupation. He assumed that iron was unknown in the subcontinent before the expansion of the Achaemenid Empire into Gandhara during the 6th century BC. The ditch and rampart identified in trench CHIII were attributed to rebuilding after Alexander the Great’s invasion of the region in 327BC. Wheeler also introduced some other key chronological reference points, such as the introduction of Northern Black Polished Ware between 300-150BC, and Gandharan schist carvings between 200BC-200AD.

However, due to later archaeological discoveries across South Asia, several scholars highlighted the inconsistencies in Wheeler's chronology, and consequently the establishment of a chronometrically based chronology became a key objective of the Charsadda (Pakistan) Project. As such, thirteen radiocarbon samples were taken from the four trenches, and processed at laboratories in Oxford and Groningen. These dates were then further constrained through the use of Bayesian statistics and OxCal.

From these dates, the Charsadda (Pakistan) Project has identified that the Bala Hisar was occupied as early as the 14th century BC, as opposed to the 6th century BC as thought by Wheeler. At this time a small community was established on a low mound of clay rising above the floodplains of the Kabul and Swat Rivers. Initially erecting structures of timber posts slotted into postholes, clay slabs were later used for the construction of more substantial structures. During this period a number of features were cut into the eastern edges of the mound, including a potential fortification ditch.

Linked to a wider regional pattern emanating from the Northern Valleys, by the first millennium BC there is a discernable Gangetic influence visible at the site. A fortification complex consisting of wall and ditch is superimposed on the earlier features and marked the eastern edge of the natural clay mound. A much more substantial retaining wall was constructed during the 2nd-3rd century BC, but our understanding of the later levels is still unclear. There is further evidence of occupation between the 11th/ 12th and 18th century at the site.