After Ramayana, Mahabharata, and Bhagavata, the most important, but lesser known book of ancient India to be read is the Kathasaritsagara. Kathasaritsagara is the largest ancient collection of stories. While Ramayana, Mahabharata, and Puranas like Bhagavata deal with stories of righteousness and spiritually, ie:Dharma and Moksha, Kathasaritsagara deals with material aspects like wealth and love, ie:Artha and Kama. Thus, these four books give one a complete insight into the four goals of life, namely Dharma, Artha, Kama, and Moksha. All are indeed important for our life, and the Indian way of enlightening them through stories is excellent. The Kathasaritsagara,which means an ocean of rivers of stories, is a huge collection of stories of daring kings,princes and princesses, lovers,lusty people,courtesans, cheats,merchants,mendicants,magicians, witches,animals,strange creatures like vetal etc.Stories of all types of genres can be seen here. They reflect on the life of different people in ancient India.They are not only entertaining but many have worldly moral and wisdom.Kathasaitsagara was written by the poet Somadeva bhatta of Kashmir in eleventh century to please Suryamati, the queen of King Anantadeva.He has written it in Sanskrit in poetic form.There are twenty two thousand shlokas or verses,and the book is divided into eighteen parts called lambakas and many chapters in them. Thus it is a very big book. The Kathasaritsagara is a summarised account of a much earlier story collection called Brihatkatha, meaning big story, written by the poet Gunadhya in a prakrit dialect (Prakrit is the spoken form of Sanskrit and there are many dialects in it)called paishachi.But this book is not available today. Long before itself it has become unavailable. Three authors summarised it in Sanskrit,and one of them is the Kathasaritsagara of Somadeva. The other two are, Brihatkathamanjari(A big collection of stories) of Kshemendra, also of Kashmir, and Brihatkathashlokasangraha (big collection of verses of Brihatkatha) of Budhaswamin, of Nepal. Kathasaritsagara is the biggest of the three and Brihatkathashlokasangraha is incomplete. Both Kathasaritsagara and Brihatkathamanjari resemble very much in content, but the Brihatkathashlokasangraha differs a lot from them. The main theme story all the three is how Naravahanadatta, the son of King Udayana becomes the emperor of Vidyadharas, a type of celestial beings who possess many sciences or vidyas. In this process, the Prince marries twenty eight beautiful girls and each of his marriage is an adventure. The former two, while narrating this main story, narrate many substories, and we get lost in the huge collection of such stories, missing often the main story itself. The characters in the story itself narrate substories to illustrate certain ideas and thus the stories develop. It can be compared to a Chinese box, which has box in a box system. Here too we have story within a story system. This is of course the tradition of all Indian stories like Ramayana, Mahabharata, Puranas, Panchatantra etc. However, the third one, namely, Brihatkathashlokasangraha,though has substories, mainly concentrates on the story of Naravahanadatta. Some scholars opine that this is probably earlier than the other two versions of Brihatkatha, and it is much closer to the original. Another reason for this is that, there is a Jain version of Brihatkatha called Vasudevahindee (Travels of Vasudeva), which very closely resembles Brihatkathashlokasangraha. This book, composed in Prakrit by Sanghadasagani and Dharmadasagani, relates the travels and adventures of Vasudeva, the father of Krishna. Vasudeva is the romantic hero of this book, and he appears as the replacement of Naravahanadatta. He, in the same way as Naravahanadatta, marries twenty eight princesses, in different wonderful adventures. His stories get interspersed with many interesting substories, some highlighting Jain principles. Apart from these four versions of Brihatkatha, there is also a Tamil version called Perungathai, meaning the same, Brihatkatha, or big story. Here, the story of Udayana is concentrated rather than Naravahanadatta.It is also incomplete. A king called Konguvelir of Kongunadu wrote it.It also has Jain aspects,rather than Shaiva aspects as seen in Kathasaritsagara.It appears that he took his material from another Sanskrit version by a Ganga king called Durvineeta. This Sanskrit version is lost, and it is mentioned that it was written by Durvineeta in an inscription obtained in Gummareddy palya near Kolar of Karnataka.Thus we have six versions of Brihatkatha,of which one Sanskrit version of Durvineeta is lost.The others are, to repeat, Kathasaritsagara of Somadeva, Brihatkathamanjari of Kshemendra, Brihatkathashlokasangraha of Budhaswamin, Jain Prakrit version Vasudevahindee of Sanghadasagani and Dharmadasagani, and Tamil version Perungatai.
There are two other books similar to Brihatkatha.One is the Brihatkathakosha, meaning the great treasury of stories. This is a collection of Jain stories written in Sanskrit by Harishena, and it is not related to Brihatkatha. There are many Kathakoshas or Jain story collections in Sanskrit and Prakrit, Apabhramsha dialect, and also in old Kannada by many authors. These collections are similar to Kathasaritsagara having a variety of stories, many highlighting Jain principles.
There is a book called Brihatkathamanjari in Kannada also.This was written by Gudarapalli Hariramashastri who claims that he took his material from a Sanskrit version by Vararuchi. But that Sanskrit version is not available. This is not the same as Kshemendra's Brihatkathamanjari. Here, the hero is King Vikramaditya, who travels with Vetala to an island where there are only females who hate males. Four sisters,the rulers of the island, sit silently covering themselves with curtains and have put up a challenge that any male who can make them talk thrice in the night can marry them or else become their slave. Vikramaditya takes up the challenge and the Vetal, entering the pictures in the curtains and also in their dresses, narrates different stories, and make them speak, thus defeating them. Vikramaditya marries them and takes them to Ujjain.
Thus, the Brihatkatha, being the largest collection of ancient Indian tales, though lost, is available in different versions, the chief one being Kathasaritsagara.The popular stories of Panchatantra and the riddlic stories of Vetala have their origin in it. The famous stories of Arabian nights,many European fairy tales,Grimms and Anderson's fairy tales, Canterberry tales of Jeffery Chaucer, Decameron of Boccacchio,and even Shakespeare's tales are influenced by it.
The Kathasaritsagara was first translated into English by C. H. Tawney, to which elaborate notes were written by N. M. Panzer, which is available in ten big volumes. Also many smaller condensed versions are available in English and Kannada. The best book is in Kannada called 'Kathamrita' by A. R. Krishnashastry.I too have written a book in Kannada called 'Kiriyara Kathasaritsagara ',the Kathasaritsagara for young, published by Sapna Book house.
Reference :Introduction to Kathamrita(Kannada) by A. R. Krishnashastry and other sources.