Sēkkilān Mādēvadigal Rāmadēva (12th century CE), known popularly by his family name as Sekkizhar, was a saint and a contemporary of Kulottunga Chola II. He compiled and wrote the Periya Puranam (Great Story or Narrative) in 4253 verses, recounting the life stories of the sixty-three Shaiva Nayanars, the devotees of Shiva. Sekkilhar himself was later canonised and his work, the Periyapuranam became the twelfth and final book of the sacred Saiva canon.
Sekkilhar was born as Arulmozhithevan, meaning the one of the divine language. He was a native of Kundrathur village (a suburb of the present-day Chennai), a sub-division of Puliyur-kottam in Thondaimandalam. Sekkilhar was a child of precious genius and having noticed this, king Anapaya, that is Kulothunga Chola II appointed him as his Prime Minister on account of his talents. His life is celebrated by Umapati Sivacharya in his fourteenth century work (1313 CE) called Sekkilhar Nayanar Puranam. Sekkilhar had the title Uttama Chola Pallavan and his brother, the title Tondaiman Pallavaraiyan. Sekkilhar is also called Ganga-kula tilaka (the glory of the Ganga race) and Bagirathi-kula tilaka (the glory of the Bhagiratha race) by Umapati Sivacharya in his work, the Sekkilar Puranam. The Guru Puja festival for Sekkilhar is celebrated annually in the month of Vaigasi-Poosam (May-June).
Kulothunga Chola II, then a young king, was a devotee of Lord Siva at Chidambaram and continued the reconstruction of the center of Tamil Saivism that was begun by his ancestors. At the same time, he was very interested in the highly erotic Jain epic Jivaka Chintamani. Sekkilhar, upon noticing this, advised the king to instead turn his attention to the lives of the Saiva saints as described by Sundarar in his Tiruthondar Thogai.
The king thereupon invited Sekkilhar to expound the lives of the Saiva saints in a great poem. Since Sekkilhar was a scholar in both the Vedas as well as the Agamas and being a Saiva saint himself, knew about Nayanmars.