Five-faced Lord Siva, out of his compassion for everyone, gave the world the Saiva Agamas. The Saiva Agamas emanated from Lord Siva’s Isana face. Thirumoolar, in his Thirumandiram, talks of the greatness of the Saiva Agamas, and therein he mentions that 66 devotees learnt the 28 Saiva Agamas. However, according to Thirumoolar, the number of Agamas is immeasurable, said R. Narayanan in a discourse.
The 28 Agamas have a total of 207 upa Agamas. The upa Agamas for the first 10 agamas are as follows: Vaktaara, Narasimha (Mrugendra) and Bhairavottara for Kamika; Vinasikhottara, Tara, Santa, Santati and Atmayoga for Yogaja; Sucintya, Sudaka, Vama, Papanasa, Parodbhava and Amruta for Cintya; Kaarana, Paavana, Daurga, Maahendra, Dinasamhita, Maarana and Vidvesa for Kaarana; Prabhuta, Parodbhuta, Parvati Samhita and Padma Samhita for Ajita; Ameya, Sabda, Acchadya, Asankhya, Amritaujasa, Ananda, Madhavodbhuta, Adbhuta and Akshaya for Dipta; Sukshma for Sukshma agama; Atita, Mangala, Suddha, Aprameya, Jatibhak, Prabuddha, Vibudha, Hasta, Alankara and Subodha for Sahasra; Vidyapurana, Vasava, Nilalohita, Prakarana, Bhutatantra, Atmalankara, Kasyapa, Gautama, Aindra, Brahma, Vasishta and Isanottara for Amsuman; Suprabheda for Suprabheda.
The first 10 Agamas beginning with Kamika and ending with Suprabheda are known as Siva bheda. Thus we find that for some of the Agamas, which fall under the Siva Bheda classification, there are many upa agamas, or secondary agamas. For some Agamas like Suprabheda or Sukshma, there is only one secondary agama. It is evident from the large list of Agamas and their subsidiary Agamas that Agamic study is in itself a specialised field, and requires great commitment for one to understand their philosophical foundations.