Middle Tamil is attested in a large number of inscriptions, and in a significant body of secular and religious literature. These include the religious poems and songs of the Bhakthi poets, such as the Tēvāram verses on Saivism and Nālāyira Tivya Pirapantam on Vaishnavism, and adaptations of religious legends such as the 12th-century Tamil Ramayana composed by Kamban and the story of 63 shaivite devotees known as Periyapurāṇam. Iraiyaṉār Akapporuḷ, an early treatise on love poetics, and Naṉṉūl, a 12th-century grammar that became the standard grammar of literary Tamil, are also from the Middle Tamil period.