According to The Siddha System, Lord Shiva is claimed to be the First and Foremost Siddhar who had attained all Siddhis.His knowledge was then imparted to Goddess Parvathi and from there to Nandi Thevar and the Navanath Siddhars. These Siddhars in turn spread their knowledge to the Famous 18 Siddhars.
The period when they live is vague and is under discussion. But mostly it was in B.C. Siddhars have shared their knowledge in the written palm leaves and these have records of knowledge on different aspects of todays modern world like medicine, psychiatry and surgery.
Siddha System comprises of various important sciences-Like Astrology, Varma, Medicine, Spirituality, Yoga, Meditation. Many of todays advanced technologies have been already spoken about in this ancient system.
The 18 Siddhars were
Agapai Siddhar Pambatti
Yogi muni Pulipani
The Siddhars were medicants and ascetics who travelled a great deal through jungles and collected various herbs and treated people in villages. Treatment was considered to be a major mission of their duties and they wrote their research and findings with the help of their disciples on palm leaves. The most astonishing fact is that the siddhars lived for many thousands of years and only they knew the secret to Kaya Kalpa and Transmigration of soul.
Historical facts help to substantiate the time when the siddhars lived. Bogar the great alchemist lived during the period of King Raja Raja Chola. Historical facts and evidences state that he helped the king to solve his architectural problems and progress with the building of the Big Temple in Thanjavur. Another theory was that Bogar was a chinese and he had an advanced knowedge of pottery skill with these techniques and his alchemy knowledge he was able to craft the 9 poision Muruga statue at Palani. Till today the idol stands and when it is anointed with honey or coconut water, the resulting mixture possess medicinal properties. When this is given to devotees, it helps cure certain uncurable diseases. The medicinal microparticles are released into the food substance and hence exhibits its medicinal properties.
Many of the hills in the south have been the favourite haunts of the siddhars where they have been in caves to make their penance or collect their valuable herbs in the surrounding forest.
Sage Agasthya is associated with Pothegai hills, Bogar with Palani hills, Kalanginathar with KanjaMalai, Ramadevar with Alagar Malai, Sattanathar and Korakkar with Saturagiri, Konganavar with Konganapuram hills and Pambatti, Korakkar, Agastya and Avvaiyar with Kolli hills. Even till today people believe and have witnessed that the siddhars visit their hills and caves in the form of light. Trekking to their hills and meditating in their caves helps one to progress in his spiritual path with their guidance and blessings.