Tirumular (also spelt Thirumoolar etc., originally known as Sundaranātha) 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.

Tirumantiram contains a synthesis of knowledge drawn from the Upanishads, Siddhayoga and the devotional (Bhakti) revival, yet criticises ritualistic idolatry and the external gymnastics of occult practice. It is deep, simple, cryptic and polyvalent.


Legend has it that Tirumular was a travelling Shaiva saint and scholar from Kailash who used his yoga powers to transmigrate into the body of a southern cowherd, Mulan. He woke up from his yogic trance once a year and composed one verse until he attained salvation.


The dates of Tirumūlar's life are hotly contested 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.


The first known reference to Tirumūlar that specifies that he was the author of a work called the Tirumantiram appears to be that of Sekkizhar (Cēkkilar) in his Periyapurāṇam, a work that was composed in the twelfth century A.D. Verse 74 of the Tirumantiram makes the claim that Tirumūlar lived for 7 aeons (yuga) before composing the Tirumantiram.[1] 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 AD, pointing out that Tirumūlar 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.[2] 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 eleventh or twelfth century AD.[3]


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.