India has always been the cynosure of other world communities in matters spiritual and intellectual. Two factors enhanced the awareness about india, abroad. These are Ayurveda and yoga. We can feel prowd that india contributed these two sciences to the world.
 Ayurveda is perhaps the oldest medical system in the world. Some his torians place the origin of Ayurveda between 2000 and 3000 years B.C. The two texts “Caraka Samhita” and “Susruta Samhita” are the pillars of Ayurveda. The “Pakshshila” University was existing in the 7 century B.C. and Ayurveda was taught there. An Ayurvedic physician of Pataliputra, Jeevaka, was a student of this University. Legend says the Jeevaka was the physician for Gautama Buddha.
 Ayurveda was a system ‘born’ from the vedas, specifically “Athawana Veda” . The core principles of Ayurveda are found in the Atharvana veda, In Rig Veda there is a mention about the celestial physicians, the twin Aswini Brothers, fitting an artificial leg made of Iron, to a person who lost his leg they also restored the eye sight of one blind person.
 During the war between Rama and Ravana (described in the well known epic Ramayana) Rama & Lakshmana get hit by a spear from Indragith, son of Ravana, and fall down un-conscious. Hanuman went and brought the Sanjeevini mountain it self which, had four rare herbs
1. Herb that eliminates poison from the body (Vishalayakarni)
2. Herb that unite the injured parts (Sandhankarni)
3. Herb that restores the bodily structures of injured parts (Savarnkarni) and
4. Herb, that brings back consciousnests revives life (sanjeevini) of these four, sanjeevini was used to bring back Rama and Lakshmana to consciousness. 
Ayurveda emanated from Lord Brahma, according to Acharya Caraka. He
taught it to Daksha Prajapathi who passed on the science to the Aswini Brothers. The brothers revealed it to Indra, Lord of the “Devas”.
 Once a group of 50 Rishis gathered at the foot hills of Himalayas and discussed about the diseases that plagued the human beings and the solutions for these ailments. They decided to approach Indra and the Maharishi Bharatwaj was elected to go and meet Indra. Indra taught all aspects of Ayurveda to the Rishi – the causes of the diseases (Hetu), the symptoms (linga) and the remedies (aushadi). Maharishi Bharatwaj assimilated all these knowledge and passed on this knowledge to other Rishis, from whom it reached the son of Atri, Punarvasu Athreya. Athreya has six disciples
1. Agnivesa
2. Bhela
3. Jatukarna
4. Parasara
5. Harita and
6. Ksharpani
Mean while, it is said that Acharya Susruta approached Dhanvantri (Lord
of medicines and king of kasi) for getting instructed about Ayurveda. He was duly taught Dhanwantri, who is considered to be the God of Ayurveda and worshipped as sueh.
 Probably the year 1500 B.C., Ayurveda divided into two major branches. General medicine, treatise on which was complied by Athreya and Surgery, treatise on which was authored by Susruta. The texts on these two branches of Ayurveda were divided into the following two categories:-
1. Brihat trayi – Containing classical texts of Caraka Samhita, Sushrut Samhita and Ashtanga Hridaya.
2. Laghn trayi – Includes Sarangadara Samhita, Bhava Prakash and Madhavinidan.
As said earlier, Agnivesa, the disciple of Athreya complied a new, the texts
of Athreya and brought out the “Agnivesa Samhita”. Agnivesa probably lived in the year 1500 B.C. His Samhita was again updated and rewritten by the great Ayurveda Acharya, Caraka. Thereafter the complied treatise was lived around 1000 B.C. The complete Caraka Samhita is not available because air the period of time, some parts of it were destroyed. Acharya Drida bala, in the I century A.D., completed it. Some experts say this was in the 9th century A.D.
 In the 4th century A.D. Acharya Vegathatta wrobe the Ayurvedic text “Astanga Hridya”. This was amended and rewritten in the 10th century us Chandrahat. Acharya Susruta, based on the teachings of Lord Dhanwantari, wroke the main text on surgery and opthalmolgy.
 We sea find a lot of explantory commentaries on Vedas, Upanishads, Gita and “Thirukkural” similarly, there are a lot of explanatory commentaries on Ayurveda texts. Similarly in the 20th century, several explanatory commentaries were written on Caraka Samhita Susruta Samhita etc.
The main texts
1. Caraka Samhita, available as of now, is in the form of verses, written in Sanskrit. It has 8 sections and 120 chapters. The wonder of this treatise is adoption of group discussion  on health issues, just like our modern group discussions and meetings. Several physcians gather and discuss a particular medical issue in detail and decide the best way of treatment. The theoretical part and the conclusion all are included in the Caraka Samhita, in detail. In this Samhita, Pathology of diseases is explained elaborately; and psycho – somatic themes are stressed and treatment prescribed includes treating the mind as well as the body. Description of ‘Pancha-karma’ treatment is found in Caraka Samhita. The Caraka Samhita, as said earlier, was brought to the present shape by the kashmiri pandit, Dridabala.
2. Surruta Samhita:- Acharya Susruta was a surgeon. He did plastic surgery in days of yore! He carried out cataract surgery also. His Samhita contains 6 sections and 186 chapters. He describes 101 blunt and 21 sharp surgical instruments. Susruta was a versatile surgeon. In his samhita, methods of dissection. Anaesthesia, Treatment for fractures, surgical treatment for Ear, nose and throat all these are described. Susruta himself carried out cosmetic surgery, caesarean operations, fixing artificial legs by surhery etc!
3. Astanga Hridyam This compilation by Acharyn Vayabhatta contains 6 sections and120 chaptres. This treatise includes important themes culled from both Caraka and susruta Samhitas. One more larger treatise, called ” Astanga Sangraha” appeared later than Astangn Hridiya and the author of this “nigandu” was also named vagabhatta. Whether these vagabhattas are one and the same is not known. Ayurvedic physicians of south India, especially of kerala follow mainly the ‘Astanga Hridiya’. The above three belong to the category of “Brihat Trayi”.
Treatises belonging to the ‘Laghu trayi’:-
1. Saranga = dara Samhita:- This was written by saranga dara in the year 1300 A.D. Its special feature is – it describes several methods of diagnosing diseases – reading of pulse etc. It also describes breathing exercises and methods of preparing Ayurvedic medicines.
2. Medhavndam Samhita:- The lexicon was written by Madhavkar in the 7th century A.D. this also contains methods of diagnosis, described clearly. This samhita details methods of preparing Ayurvedic medicines.
3. Bhava Prakash Samhita:- This was written Bhavamisra is the 13-14th centuries A.D. It includes family planning methods, medicines and discription of Veneral diseases.
A part pom these three, another Samhita, called Kashyapa Samhita
exists. This mainly deals with paediatrics. But unfortunately this samhita is not available is in full form. Only some sections are available.
 Ayurveda formed such a uride, solid foundation lost its continuity and practice during the foreigneis rule of India. Now there is a revival – Ayurveda again is making a strong come back.