Iconography of Shiva temples in Tamil Nadu is governed by the Shaiva Agamas (IAST:Āgama) that revere the ultimate reality as the Hindu deity, Shiva. Āgama (Sanskrit: आगम, Tamil:ஆகமம்) in the Hindu religious context means a traditional doctrine or system which commands faith. Temple worship according to Āgamic rules can be said to have started during the Pallava dynasty (551-901 A.D.) in South India, but they were fully under establishment during the Chola dynasty (848-1279 A.D.) The temples during the Chola period expanded to Sri Lanka and islands in South East Asia. The temple complex was expanding with niches for various deities on the stipulated sides of the sanctum. Lingam was universalised and prakarams (precincts) with subsequent deities came up. The temple parivara(deities related to primary deity) expanded considerably during the Chola period. The niches of following Āgamic rules for building Shiva temples in Tamil Nadu, a South Indian state continues even in the modern era. Some of the prime images like that of lingam, Vinayagar and Parvati are present in all the Shiva temples. Almost all the temples follow the same custom during festivals and worship methods with minor exceptions. Most of the Shiva temples in Tamil Nadu and Sri Lanka (like Munneswaram temple, Koneswaram temple, Tennavaram temple, Ketheeswaram temple, Naguleswaram) are built in Dravidian architecture.