Bṛhatkathā, also known as "the Great Narrative," is an ancient Indian epic believed to have been written by Guṇāḍhya in a language called Paiśācī, the language of common people of the border regions of Northwest India, which is not well understood. While the original text is lost, there are several later adaptations in both Sanskrit and vernacular languages which provide commentary on the work. The exact date of the composition is uncertain, but based on references made by later Sanskrit poets such as Daṇḍin, Subandhu, and Bāṇa, it is believed to have existed in the 6th century CE or even earlier. For instance, if the story of Udayana by poet Bhāsa, which was also adapted by Harśa in Ratnāvalī, was inspired by Bṛhatkathā, it would have to be older than Bhāsa's time, estimated to be before the 3rd century CE.The work narrates the adventures of many big traders (Written in story in story style), who scaled the mountains churned the ocean in search of wealth of gold, gems, pearls etc. According to the story, Guṇāḍhya was only able to preserve 700,000 Ślokas, while the author himself destroyed the remaining ones out of frustration.
The reason for Mālyavān being cursed by Pārvatī and forced to be born as a human who is Guṇāḍhya himself has a backstory. Once Pārvatī asked Śiva to tell her a unique and interesting story that no one had heard before. To ensure privacy, Nandikeśa was instructed to guard the door and not allow anyone inside while Śiva narrated the story of the Vidyādharas to Pārvatī. However, Puṣpadanta, who was the chief of the genie-guards of Śiva and had unrestricted access to him, entered the room without permission and heard the story standing in a concealed spot. He later shared the story with his wife, Jayā, who, on another occasion, told it to Pārvatī, who was upset to hear a story that she believed was supposed to be unique. After some investigation, Śiva found out how Puṣpadanta had obtained the story and explained it to Pārvatī. She then cursed Puṣpadanta and Mālyavān, who spoke on Puṣpadanta's behalf, turning them both into humans. Pārvatī then revealed that the curse could be broken by telling the story to a devil named Kāṇabhūti, who resided in the Vindhya mountains. Puṣpadanta was reincarnated as Vararuci in the city of Kauśāṃbī, and Mālyavān as Guṇāḍhya in the city of Supratiṣṭhita. They were instructed to share the stories they had heard from Kāṇabhūti and only then would the curse be lifted from them. It took Guṇāḍhya seven years to create a Mahākāvya by writing stories in the satanic language and compiling them into seven lakh granthas. He faced the challenge of not having any writing materials and had to resort to using leaves, blood, and twigs. Once he began reading his book, all the devas gathered in the sky to listen. Upon hearing it, Kāṇabhūti was released from the curse. This book, which contains seven lakh granthas, is known as the Bṛhatkathā.
When he finished the book, his disciples suggested that he present it to King Sātavāhana to ensure its survival. However, when the King read the book, he didn't like it due to its elaborate language and satanic nature. Guṇāḍhya, feeling dejected, burned all but one lakh of granthas in a fire-pit, with his disciples watching in tears. The wild animals of the forest also flocked to the place to listen to Guṇāḍhya's reading before he burned each leaf. Meanwhile, the King fell ill, and it was discovered that the dry flesh he had been eating was the cause. The hunters who supplied the meat reported that all the animals were gathered around Guṇāḍhya, listening to him read and burn his book. Sātavāhana fell ill and the palace physicians attributed it to the dry flesh he had been consuming. The cook accused the hunters who supplied the meat, and upon questioning, the hunters revealed that they could only obtain such meat as all the animals were listening to Guṇāḍhya, who was reading from a book and burning the pages. Sātavāhana went to Guṇāḍhya and prostrated before him. Guṇāḍhya spoke in a satanic language, telling Sātavāhana his story from the curse on Puṣpadanta to the destruction of his own work. He gave Sātavāhana the remaining one lakh of granthas and then jumped into the fire. Sātavāhana and the disciples of Guṅāḍhya went back to the palace with the 'Bṛhatkathā', which contained the story of Naravāhanadatta. The King added a preface to the book explaining how it came to be written in a satanic language, and it became very famous. (Pīṭhānulaṃbaka Kathāsarit sāgara).
In the Bṛhatkathā, Guṇāḍhya has been unique where author has spoken in the first person. Unlike Vedavyāsa and Valmiki, who are represented by an unseen narrator, Guṇāḍhya's story is told from his own perspective.
The Bṛhatkathā which was originally in Paiśācī, was first translated into Prakrit, but that version is no longer available. The closest version to the original Bṛhatkathā is the Sanskrit translation by Buddhasvāmī known as the Bṛhatkathā -slokasamgraha. Of the existing works, the two other versions were written by Kashmiri writers named Ksmendra and Somedeva. Ksmendra's version is called the Bṛhatkathāmañjarī, and Somedeva's version is called the Bṛhatkathāsāgara. The Bṛhatkathā of Guṇāḍhya has made a significant contribution to Sanskrit literature, comparable to that of the epics. The greatest contribution of Bṛhatkathā is Mṛcchakaṭika its plot, theme etc. all are borrowed by Śūdraka with a difference which tell about the time-gap & developments pertaing to social, relgious & political life of the country. It has been a source of inspiration for many oher renowned writers such as Bhāsa, Śūdraka, and Kālidāsa, who have drawn ideas from this extensive work. The Bṛhatkathā acted as a mainspring for works such as ‘Mudrārākṣasa’ ‘Ratnāvalī’, ‘Pañcatantra’’, Mālatī-Mādhava’, ‘Nagānanda’ etc.