Ten of the pillars bear inscriptions and are located in Lauriya-Nandangarh, Lauriya-Araraj, Rampurva, Sarnath and Sanchi in India, Nigali Sagar and Rummindei in present-day Nepal, two pillars from Topra and Meerut which were relocated to Delhi by Firoz Shah Tughlaq in the fourteenth century, and one pillar in Prayagraj (previously known as Allahabad) which may have originally been erected at Kosambi. Fragments without inscriptions have been found at Bodhgaya, Kosambi, Gothawa, Hisar, Prahladpur, Fatehabad and Khushinagar. Of these, seven pillars — one each from Sarnath, Sanchi, Vaishali and Lauriya-Nandangarh, and two from Rampurva — have been found with capitals. The accounts of the traveling Chinese monks Faxian and Huientsang mention six and fifteen pillars respectively along with their locations; from the latter list, only five have been identified, the remaining pillars have not been recovered so far.

Many of the pillars were erected at centers of Buddhist importance, such as Sarnath or Sanchi, and were thus also close to monasteries. The choice of the pillar to spread his edicts suggests that Ashoka was emulating the circumambulatory path of Buddhist rituals in inscribing them. The edicts indicate that the pillars were erected with the purpose of propagating the emperor’s morally didactic message and his Dhamma policies (Sanskrit, Pali: meaning “to hold, maintain, keep”) for maintaining a lifestyle informed by everyday morality, such as respect for one’s elders and lessers.

The Minor Pillar Edicts are dated to the twelfth year of Ashoka’s reign, around 257-256 BCE. Scholars are of the opinion that the Minor Pillar Edicts were inscribed by sculptors and engravers who had access to simple methods of handling the stone, in a time when stone engraving was relatively new in the Indian subcontinent. It has been suggested that the degree of skill visible in the Sanchi and Sarnath capitals could be attributed to hired Persian sculptors from the erstwhile Achaemenid Empire (dissolved in the fourth century BCE), who were trained in Hellenistic sculpture. Alternatively, the artisans may have simply been new to inscription as a craft.

The Schism Edicts, written on the Sarnath, Sanchi and Prayagraj pillars, outline an injunction against schism in the Buddhist Sangha. The inscriptions order the Mahamatra to expel monks and nuns who disagree to the point of creating an ideological break within the Sangha, and also bar such individuals from entering the clergy. An additional edict on the Prayagraj pillar, also known as the Queen’s Edict, states that charitable projects initiated by Kuravaki — Ashoka’s second queen — should be counted towards her credit of good deeds. The inscription from the Lumbini pillar states that it was erected to mark Ashoka’s pilgrimage in his twentieth regnal year (ca. 249 BCE) to the birthplace of the Shakyamuni Buddha, and that the Mauryan court would take an eighth of Lumbini’s agricultural produce in lieu of taxes. The inscription on the Nigali Sagar pillar, also made in 249 BCE, mentions Ashoka’s expansion of a nearby Kanakamuni Buddha stupa six years previously, although no remains of this stupa have been found.

The last of Ashoka’s edicts are the seven Major Pillar Edicts, all inscribed in Ashokan Prakrit in the Brahmi script. The six pillars bearing these inscriptions are at Lauriya-Nandangarh, Lauriya-Araraj, Rampurva, Prayagraj, and two at Delhi which were moved from Topra and Meerutin the fourteenth century by Feroz Shah Tughlaq. Of the two pillars at Rampurva, only the one topped with a lion capital is inscribed.

The first Major Pillar Edict, issued in Ashoka’s twenty-seventh regnal year, details on the policy of achieving happiness by observing moral conduct, obedience and energetics, a policy that is maintained by the Dhamma Mahamata patrolling the border regions of the Mauryan Empire for managing and disposing of the affairs of people. The second Major Pillar Edict outlines the merit of observing the policies of Dhamma: fewer sins, virtuous deeds, compassion, liberality, truthfulness and purity. Ashoka claims to have a gift for spiritual insight, one of the many blessings he received by practicing Dhamma. The third Major Pillar Edict is a call to condemn the sinful deeds of pride, anger, envy, fierceness and cruelty, an action taken to ensure happiness in this world and the next. The Fourth Major Pillar Edict details the executive, administrative and judicial duties of Rajukas, lists pardons given to prisoners, and grants death row prisoners three days to plead their sentences. The Fifth Major Pillar Edict, issued after the king’s twenty-sixth regnal year, issues orders prohibiting the killing of parrots, wild geese, bats, terrapins, tortoises, porcupines, ants, boneless fish, rhinoceros, bulls and squirrels. Ashoka also decreed a certain number of days on which no animals would be killed or consumed, castrated or branded, and that forests should not be burned. The Sixth Major Pillar Edict, issued in Ashoka’s twenty-sixth regnal year (ca. 242 BCE), explains the Dhamma policy of the king according to which he acted with moral conduct, performing deeds of virtue, courtesy and respect to assist his people in attaining happiness.

The Seventh Major Pillar Edict only occurs on the Delhi-Topra pillar, and features longer inscriptions compared to the other pillars; parts from other Pillar Edicts and some Major Rock Edicts are summarised throughout the Seventh Pillar Edict. It appears to be testimonial in nature, summarising parts of the other Edicts while listing Ashoka’s reign in terms of its spiritual and civic accomplishments: namely the construction of the pillars, the appointment of the Dhamma Mahamatra and extending their jurisdiction to the Buddhist Sangha, Brahamanas, Ajivikas and Jain sects, the planting of trees, distributing gifts from the court, the provision of watering holes for migrating animals, building rest houses and so forth.

Scholars have raised doubts around the date and authenticity of the seventh edict, suggesting that it may have been a much later physical compilation of edicts from other pillars, which were then transcribed onto the Delhi-Topra pillar. The inscriptions on the pillar are lightly marked, almost scribbled, and do not appear to have been done by the same artisans as the others. Further, mentions of the Buddhist Sangha, Brahamanas, Ajivikas and Jain sects are unique to the Seventh Edict, and do not occur on the other Pillar Edicts.

There is much speculation over the design of the pillars and their respective capitals. Some scholars have compared the style and motifs of the Ashokan capitals to designs used in Achaemenid Persia and later Hellenistic Greece, possibly through a style which gained popularity throughout the ancient world, and became a source of inspiration for Indian variations. This influence is speculated to have arrived in the form of Persian sculptors employed to construct the pillars and capitals by the Mauryan Empire, although this is disputed. The pillars and their capitals have also been compared to dhvaja (Sanskrit, meaning “banner” or “flag”), the military standard carried by soldiers during war, based on a carved image on the railing from the Bharhut stupa, which depicts a royal person carrying a Garuda standard.

Despite the possible influences from contemporaneous traditions in Persia, Mesopotamia and Greece, the Ashokan pillar is structurally distinct: they are designed as monoliths, while the Persian pillars are built in segments; Persian pillars have fluted bodies, while the Ashokan pillars have a polished, smooth body. And while Persian pillars served an architectural purpose as supports, the Ashokan pillars are free-standing monuments.

While the edits are generally attributed to Ashoka, some of the actual pillars — particularly those without capitals — may predate his reign, and may have been inscribed on his instructions. Since further information about this is unknown, it is generally assumed that Ashoka is primarily responsible for erecting the pillars, since the edicts and capitals he commissioned give the pillars their historical value.