Tirumular (also spelt Thirumoolar etc., originally known as Cuntaranātar) was a Tamil Shaivite mystic and writer, considered one of the sixty-three Nayanars and one of the 18 Siddhars. His main work, the Tirumantiram (also sometimes written Tirumanthiram, Tirumandhiram, etc.), which consists of over 3000 verses, forms a part of the key text of the Tamil Shaiva Siddhanta, the Tirumurai.
The dates of Tirumular's life are controversial, and because his work makes reference to so many currents of religious thought, the dates that different scholars assign are often appealed to for anchoring the relative chronology of other religious literature in Tamil and Sanskrit.
Some are therefore inclined to place his composition well before the Common Era. The scholar and lexicographer S. Vaiyapuripillai, however, suggested that he probably belonged to the beginning of the eighth-century CE, pointing out that Tirumular could not very well be placed earlier given that he appears to refer to the Tevaram hymns of Sambandar, Appar and Sundarar, that he used "very late words" and that he made mention of the weekdays.
Others wish to push the date still later: Dominic Goodall, for instance, appears to suggest, on the grounds of religious notions that appear in the work with Sanskrit labels for which a certain historical development can be traced in other datable works, that the Tirumantiram cannot be placed before the 11th- or 12th-century CED. Yet another view, alluded to for instance by Vaiyapuripillai (ibid.), is that the text may contain an ancient core, but with "a good number of interpolated stanzas" of later date. Whatever the case, allusions to works and ideas in the Tirumantiram cannot, at least for the moment, be used as useful indicators of their chronology.