associating Ashoka with his regnal title Devanampriya ("Beloved-of-the-Gods"): Another important historian was British archaeologist John Hubert Marshall, who was director-General of the Archaeological Survey of India. His main interests were Sanchi and Sarnath, in addition to Harappa and Mohenjodaro. Sir Alexander Cunningham, a British archaeologist and army engineer, and often known as the father of the Archaeological Survey of India, unveiled heritage sites like the Bharhut Stupa, Sarnath, Sanchi, and the Mahabodhi Temple. Mortimer Wheeler, a British archaeologist, also exposed Ashokan historical sources, especially the Taxila. Perceptions and historiography The use of Buddhist sources in reconstructing the life of Ashoka has had a strong influence on perceptions of Ashoka, as well as the interpretations of his Edicts. Building on traditional accounts, early scholars regarded Ashoka as a primarily Buddhist monarch who underwent a conversion from the Vedic religion to Buddhism and was actively engaged in sponsoring and supporting the Buddhist monastic institution. Some scholars have tended to question this assessment. Romila Thappar writes about Ashoka that "We need to see him both as a statesman in the context of inheriting and sustaining an empire in a particular historical period, and as a person with a strong commitment to changing society through what might be called the propagation of social ethics." The only source of information not attributable to Buddhist sources are the Ashokan Edicts, and these do not explicitly state that Ashoka was a Buddhist. In his edicts, Ashoka expresses support for all the major religions of his time: Buddhism, Brahmanism, Jainism, and Ajivikaism, and his edicts addressed to the population at large (there are some addressed specifically to Buddhists; this is not the case for the other religions) generally focus on moral themes members of all the religions would accept. For example, Amartya Sen writes, "The Indian Emperor Ashoka in the third century BCE presented many political inscriptions in favor of tolerance and individual freedom, both as a part of state policy and in the relation of different people to each other". However, the edicts alone strongly indicate that he was a Buddhist. In one edict he belittles rituals, and he banned Vedic animal sacrifices; these strongly suggest that he at least did not look to the Vedic tradition for guidance. Furthermore, many edicts are expressed to Buddhists alone; in one, Ashoka declares himself to be an "upasaka", and in another he demonstrates a close familiarity with Buddhist texts.