The historical setting
Ashoka, also known as Asoka or Aśoka, most commonly known as Ashoka the Great, was Emperor of Magadha from c. 268 BCE until his death, and the third ruler from the Mauryan dynasty. His empire covered a large part of the Indian subcontinent, stretching from present-day Afghanistan in the west to present-day Bangladesh in the east, with its capital at Pataliputra. A patron of Buddhism, he is credited with an important role in the spread of Buddhism across ancient Asia. The Edicts of Ashoka state that during his eighth regnal year (c. 260 BCE), he conquered Kalinga after a brutal war. Ashoka subsequently devoted himself to the propagation of "dhamma" or righteous conduct, the major theme of the edicts. Ashoka's edicts suggest that a few years after the Kalinga War, he was gradually drawn towards Buddhism.
Inscriptions
Ashoka's inscriptions are the earliest self-representations of imperial power in the Indian subcontinent. However, these inscriptions are focused mainly on the topic of dhamma, and provide little information regarding other aspects of the Maurya state or society. Even on the topic of dhamma, the content of these inscriptions cannot be taken at face value. In the words of American academic John S. Strong, it is sometimes helpful to think of Ashoka's messages as propaganda by a politician whose aim is to present a favourable image of himself and his administration, rather than record historical facts. A small number of other inscriptions also provide some information about Ashoka. For example, he finds a mention in the 2nd-century Junagadh rock inscription of Rudradaman.
An inscription discovered at Sirkap mentions a lost word beginning with "Priyadari", which is theorised to be Ashoka's title "Priyadarshi" since it has been written in Aramaic of the 3rd century BCE, although this is not certain. Some other inscriptions, such as the Sohgaura copper plate inscription and the Mahasthan inscription, have been tentatively dated to Ashoka's period by some scholars, although others contest this. The edicts of Ashoka are a collection of 33 inscriptions on the Pillars of Ashoka, as well as boulders and cave walls, issued during his reign.
Kalinga war
According to Ashoka's Major Rock Edict 13, he conquered Kalinga eight years after ascending to the throne. The edict states that during his conquest of Kalinga, 100,000 men and animals were killed in action; many times that number "perished"; and 150,000 men and animals were carried away as captives. Ashoka states that the remorse over this sufferings caused him to devote himself to the practice and propagation of dharma. He proclaims that he considered the slaughter, death, and deportation caused during the conquest of Kalinga painful and deplorable; and that he considered the suffering caused to religious people and householders there even more deplorable. This edict has been inscribed at several places, including Erragudi, Girnar, Kalsi, Maneshra, Shahbazgarhi and Kandahar.
However, it is omitted from Ashoka's inscriptions found in the Kalinga region, where Rock Edicts 13 and 14 have been replaced with two separate edicts that make no mention of Ashoka's remorse. One possibility is that Ashoka did not consider it politically appropriate to make such a confession to the people of Kalinga. Another possibility is that the Kalinga war and its consequences, as described in Ashoka's rock edicts, are "more imaginary than real".
Dharma
Ashoka's various inscriptions suggest that he devoted himself to the propagation of "Dharma" (Pali: Dhamma), a term that refers to the teachings of Gautama Buddha in the Buddhist circles. However, Ashoka's own inscriptions do not mention Buddhist doctrines such as the Four Noble Truths or Nirvana. The word "Dharma" has various connotations in the Indian religions, and can be generally translated as "law, duty, or righteousness". In the Kandahar inscriptions of Ashoka, the word "Dharma" has been translated as eusebeia (Greek) and qsyt (Aramaic), which further suggests that his "Dharma" meant something more generic than Buddhism. Modern scholars have variously understood this dhamma as a Buddhist lay ethic, a set of politico-moral ideas, a "sort of universal religion", or as an Ashokan innovation.
On the other hand, it has also been interpreted as an essentially political ideology that sought to knit together a vast and diverse empire. Ashoka instituted a new category of officers called the dhamma-mahamattas, who were tasked with the welfare of the aged, the infirm, the women and children, and various religious sects. They were also sent on diplomatic missions to the Hellenistic kingdoms of west Asia, in order to propagate the dhamma.