Agathiyar is the first among 18 siddhars. Agathiyar is considered as the guru for all Siddhars and He is believed to be direct disciple of Lord Shiva. Siddhars are the followers of Lord Shiva. He is regarded and specialized in Language, Medicine and Spirituality (Yogam and Gnanam). There are 96 books in the name of Agathiyar. The place of his Samadhi is located in Ananthasayanam.

Thirumoolar who was a Tamil Shaivite mystic and writer. He was considered one of the 18 Siddhars and one of the sixty-three Nayanmars. He flourished and lived for 3000 years. His main work, the THIRUMANTHIRAM that consists of over 3000 verses, forms a part of the key text of the tamil Shaiva Siddhanta, the Tirumurai. His masterpiece Thirumanthiram, deals with the body and soul.
Thirumanthiram is considered as heart of Thanthrik Yoga.
Thirumoolar is the prime author of famous literary works THIRUMANTHIRAM and SAIVA SIDDHANTAM which framed the basic principles of Siddha system. His hypothesis on Atomic theory is considered to be reinstated as Nanotechnology in recent times. The physiological principles which he mentioned during such ancient times are astonishing. Thirumoolar is the only Siddhar who emphasized on ‘Sound Mind in a Sound Body’ by which one can achieve mortality by kalpa yoga procedures. Versions of Thirumoolar are certainly appropriate for this modern, stressful world. It is helpful in combating non-communicable diseases such as myocardial infarction, degenerative diseases and depressive disorders. Regular practice of yoga will undoubtedly improve the over-all health. His place of Samadhi is believed to be at Chidambaram.

Kalangi was the guru of Bhogar. He was from Benaras. He is often referred to us Kanjamalai Siddhar. The word “kanjam” stands for the following meaning gold, copper and Iron and “malai” means hill. He is the disciple to the great siddha Thirumoolar. He is one among the seven disciples whom Thirumoolar transcended his knowledge, The shrine of Kalangi is found in a small village in Salem, Tamil Nadu. This village is 12 km away from Salem City. He is supposed to have attained Samadhi in this place several hundred years ago. He attained mukthi (immortal status) in Kanchipupram. His jeeva samadhi is found in Kanchipuram district of Tamil Nadu. He has a very special temple in Shivadhapauram to Ellampillai, which is called as Siddhar Koil in the same area. It is situated at the grounds of Kanjamalai.

Bogar is considered as one of the 18 siddhars. According to epigraphical sources and his book Bogar – 7000 his period is around 3000 B.C. Bogar born in India and visited China in search of truth of life, he gained knowledge in medicine, astrology, spirituality, yoga etc. Bogar anticipating that in due course of period, human beings will suffer from large number of diseases. As an expert in medicine he used 4448 rare herbs and made 9 poisonous medicine, mixing these 9 poisons into one need great knowledge and skill, to make a Master Medicine (One medicine to cure all disease). Thirumoolar also discuss one such Master Medicine in his book Thirumandiram. With the consultation of Agasthiar and other siddhars Bogar mixed the 9 poisons (Nava Bashanam) and made the Master Medicine in the form of Lord Murugan which is currently worshiped at Palani Murugan temple. There is a place near Palani Hill called Thannasiappan Temple which is the place where Bogar mixed the Nava Bashanam and made the Murugan idol. After installing Lord Murugan Navabashana idol Bogar used to worship it with milk abishegam (pouring milk on the idol) and panchamirtha abishegam (pouring panchamirtham on the idol). Bogar Samadhi is inside Palani Murugan temple at Palani Hill. Actually, Bogar himself constructed his samadhi exactly under the Lord Murugan Navabasha idol and went into Nirvigalpa Samadhi there. The entrance to his samadhi is a cave like structure, now also worship for this great siddhar is conducted at this entrance where he is last seen by his disciples which is at the Palani temple.

One person by name Sivalinga Deva udayar from Kannada Desa came to Palani and become a disciple to Bogar. He subsequently became a siddhar and got the name Pulippani, because it is believed that he brought water riding on a Tiger for the worship of Dhandapani, the idol of God Muruga at Palani. He took Palani as the place of residence as well as the place of Samadhi. There is a traditional school and a Ashramam in the name of pulippani even now. He assigned the period from 10th to 11th century A.D for about 204 years, starting from latter part of Dvapara Yuga and ending in the earlier part of Kali yuga. He is one of the important Siddhar out of 43 siddhars, who learned the art and science of Siddha system from Bogar. There are eight works that go in the name of pulippani. He disappeared in a sutchuma Nilai without undergoing physical death. The place of his Samadhi is located in western side of Durgai Ammam Temple, very near to Bogar Samadhi.

Punnakkeesar is the student of pampatti siddhar. He is named as punnakesar since his tongue been splited. His Jeeva Samathi is in Sanganachery (Nanguneri), He is one of the eighteen siddhar and believed to be the Guru for Machchamuni. He cured many people suffering from various diseases and he is very sensitive in finding the future diseases of a person going to be affected and he treats for that also, still people around Sanganachery often visit his samathi to worship him. Karuvurar make a poem on him in his vedhakaviyam.

Rama Devar is grouped among as one of the eighteen siddhars. When he visited Mecca in Arabia, he adopted himself to Muslim cult and changed his name as Yacob. There are about 24 works dealing in Siddha system that go in the name of Rama Deva Siddhar. Based on the common source of the old stanza, Alagar Malai of Madurai District is taken as the place of Samadhi for Rama Devar. He himself speaks about the final stage of Mukthi in Siddha Yogam which is otherwise known as Pooranam in his work Rama Devar 1000. The art and science of Kayakalpam has been built up in the science of siddha system. He has stressed the importance of Tamil language by saying that Sivayogam which has got a basic application for Siddha System, has been written in Arun- Thanmizh.

Sattainadhar seems to be contemporary of Karuvurar and Konganar, 10th and 11th century A.D may be the period which he belongs. His contributions include 46 known works Medicine, Alchemy & etc. His disciples include Sundaranandar, Paambatti. He has attained samadhi at Srirangam otherwise called as Jothirangam. He is habituated in Sirkazhi. Shiva is believed to have quelled the arrogance of Hindu god Vishnu, after showing his dominance over the three worlds and hence got the name “Sattainadhar” here. The town is thus called “Sattainathapuram”, which in modern times, is a suburb within Sirkazhi. There are fourty-six known works in his name some of them are Sattamuni pini gnanam 100, Sattamuni vadha kaviyam 1000,Sattamuni vatha soothiram 200, Sattamuni gnana vilakkam 51
His contributions are mainly in the fields of alchemy and 96 thathuvas. In Sattamuni gnana vilakkam 51, stanza 11, there is an observation to a fact that a siddhar by way of taking in kalpam, changes the body dhatus. In the case of sattaimuni it is told that he has changed his body dhatus for 96 times by taking kalpam this may also stand for 96 thathuvas of the human body.

Theriyar is one among 18 Siddhars. His real name, Manduga maharishi says Ramadevan Abhithana Chintamani. His writings were Vaidya Yamaka Venba and Manivenba Dharmaprata which are the foundation of Ayurvedic medicine today other some important writings are Theraiyar Karisal, Theraiyar Vaidyakaviyam, Theraiyar Vagatam, Theraiyar Tharu, Theraiyar Sekarappa, Theraiyar Mahakarisal, Neernirakkuri Neikuri, Thailavarkkachurukkam, Thinakirama Alankaram, Chikitchaikiramam, Noimarundalavai. He was named as Theraiyar, for his skillful open head surgery to the king kasivarman for removing a Therai (Toad) which resided in his scalp entered through his ears. Therayar is considered to be the master of many fields like Astrology, Mysticism, Alchemy, Medicine and Language. His scholarship and style of the language are considered to be unique.
He mastered many languages like Telugu, Kannada, Malayalam, Tamil, Thulu and Sanskrit. His Guru (Master) was Dharmasowmiyar.
His work on classification of diseases is noteworthy. The belief is that he has been buried in Pothigaimalai on the Western Ghats.

Sundaranandar is also known as Sundarar. Kiskinda hill located in Hampi in Mysore state, is the place where sundaranandar associated himself mostly. He has been assigned 11th century A.D., because he has to be taken as the contemporary of Sattamuni and Konganar. He is guided by Konganarin Siddha system. There are about 24 works on his name some important works are Sundaranandar Athisayasoothiram, Sundaranandar Vakkiyasoothiram, Sundaranandar Gnanasoothiram, Sundarar Dhantakam. His place of Samadhi is Madurai.

His work is known kamalamuni-10, speaks more about spiritual aspects of life. Kamalamuni Siddhar is said to have attained samadhi in the Tiruvarur temple. His peetam is found near the Amman shrine. Kamalamuni Siddhar also bestows on the sadhakas direct guidance on how to recite the Mahamantra and how to meditate on the susumna nadi. The great Siddhar advocates one year of intense practice to achieve great Siddhi through this instruction. Siddhar Kamalamuni also carefully guides how to combine bhakthi in this kriya yoga process. He instructs a specific order of prayer and pranayama. His tamil poems from “Jnana Chaitanyam”. very uniquely worship of the paramporul (fundamental and all-encompassing principle) as mouna (silence).

Karuvurar is also called as Karuvur Thevar. His name may also be a derivative name because of the fact that he had the capacity to understand the essence of whatever is taught to him, with an easy grasp. And another reason Karur the place which he belongs. The period to which he belongs is 11th century A.D., medieval period, In Karvurar Sivagnanabothakam stanza – 8, the importance of worship of sakthi in the form of Valai Thai or Mononmani by the Siddhars is stressed. Further the fundamentals of Panchabhuthas of Nilam, Neer, Thee, Kattru and Van including Eru Chudar of Sun and Moon and Uyir which is associated with Sakthi are also recorded. According to stanza 706 and 891 of the 6th kandam of Bhogar-7000, it is evident that he has created a statue of god Nataraja by order of Pandiya King of his time. In present moment there is a temple by the name of Karuvur Siddhar is in existence just behind the big temple of Tanjore. There is a Royal tradition which tells that Karuvur Siddhar has contributed much to the construction of Tanjore temple.

The sanctums related with Korakkar are Perur, Thiruchendur and Triconamalli. Korakkar caves are found in Chaturagiri and Kollimalai Hills. There are about 13 works in the name of korakkar. As per the available ancient stanza, Perur which is a place very near coimbatore is to be taken as place of his Samadhi. He is also called as Korakkanathar. His major contributions are Korakkar brahma gnanam 18, Korakkar brahma gnana soothiram and Korakkar karpa choothiram, Korakkar chunna soothiram. Accompanying Nagarjuna he has visited Meru Nadu doing alchemy with the help of thylam, siddhar Nagarjuna has renovated a Sparisa-Vedi-Lingam in Sreeshylam malai. It is told that by mere touching of this lingam many diseases are cured. There is one in the name of Korakkar which is called – Korakkar mooli (Indian hemp) probably because Korakkar was first in the world using often this Mooli (herb) in his preparations and so the herb is named after him.

This siddhar has singing songs ending with the word Kudambai. That is the reason why he got this name. The place which he belonged and got his siddhi is given as Mayiladuthurai which is otherwise called as Mayavaram. He got instructions from Alukunni Siddhar. His works are more towards spiritual bliss and gnana yoga His major contribution is Kudambai siddhar padalgal. He describes the condition of the released souls and secludes that they do not require most of the things that men are after. He considers that the ultimate spiritual bliss is an end in itself and that for those who have attained it there is no need even for Jnana or Yoga.

Machamuni Siddhar belongs to the place Macha Desam. He is contemporary of Konganar siddhar and Karuvur siddhar of 10th and 11th century A.D. There are about 10 works in the name of Machamuni Siddhar. The place of his samathi as given in the old stanza is Thirupparankundram in Madurai district. Machamuni accompanied Konganar Siddhar Prommar and Moolar in the pilgrimage to kailash and paid their homage to Siva and Agathiyar. He has capable of retaining the realization of the Siva Bhathi, which is eternal, permanently in his Sitham and thus got the name as Samayathittha Siddhar. In Yogagnana Sastra Thirattu there is a mention of a work as Macchendra Nahar-endra Nondhi-Siddhar Padal. In the above work, there is an observation about a Thatthuvam with regards to yogic stage. He speaks of introspective, analysis of himself in yogic practices, without the destruction to physical body in a yogic pose, he could keep himself with the help of Gnanakkan by killing the egoism, with the aid of his Guru. To attain this final stage in the yogic practice the siddhars used powerful medicines in the form of Baspams, Chenduram, Kattu, Kalangu etc., to preserve the physical body in the different stages of their yogic practices.

The most popular and well-known of these siddhars is Pambatti Siddhar(the snake chamber), Who may be taken to be a true representative of his tribe. He takes the snake for a symbol to represent the human soul and uses the expression ‘Aadu Pambe’ as a refrain at the end of each stanza of his poem that may be cause of his name. He sings Lord Shiva as the supreme power of the universe. As a poet he is not contemptible. He has a facility of expression and an imaginative flavor in thought. Chattamuni is considered to be Pambatti guru. Eight unique powers (Attama siddhis) of Siddhars are mentioned in his works. His contributions are related with gnana siddhi starting with “Aadu pambe” ( dancing snake). He is also known as Pathanjali, Nagamuni. Some of his important works are Sirorogavithi, Nayanarogavithi. He seems to belong to Maruthamalai in Kongunadu. He got instructions from Sattaimuni. His place of Samadhi is Sankaran koil of Tirunelveli district.

His works are narrated as if he is weeping for the suffering and for the wellbeing of the world. The place to which he belongs is Vairagiri. Nagapattinam is also given as his place in siddhar gnanakkovai. He got instructions from Edaikattu Siddhar. His songs about Siddha philosophy and Thatthuvam are pathetically melodies. Mystical and Yogic ideas have been dressed in a symbolism which is difficult to understand. Its popularity is probably due to its song quality. Conceiving the supreme Power as Sakti and addressing her as Kannamma, this Siddhar unburdens, in songs which have a plaintive music of their own, his thoughts and feelings which embody a mood of melancholy. One of his works is available in the printed work called Siddhar Gnanakkovai. His place of Samadhi is Nagapattinam

This siddhar was living in a place called Edaikkadu he might have got the name Edaikkattu Siddhar. It is to be differentiated between the Sangam poet idaikkadar who is the author of certain Elakkiyam with that of Edaikkattu Siddhar of the later age. The place is located in the southern part of Pandiya Nadu. He is disciple of Karur Siddhar the probable period to which he belongs should be 11th and 12th century A.D. He got instructed by Bogar in the important aspects of Siddha System. There are two works that go in the name of idaikkadar. There is one school of thought which says that a place by name Thiruedaikkodu in the kanyakumari District is the place of his Samadhi and also it is affirmed that even his Samadhi can be identified at present in that place. He took Karpam in the method of Kayakalpam for the purpose of keeping the body young, His contribution towards rasavatham and kayakarpam is remarkable also he performed Rasavadham for very long period of Time. His place of Samadhi is at Thiruvannamalai.