Sea (written around 50 CE) is often identified with the modern-day coastal town of Purakkad on the mouth of the Pamba River in the Alappuzha district. This river is also the third-longest river in Kerala only after to the Periyar river and the Bharathappuzha river. Early members of the Chera dynasty had their home in Kuttanad and were sometimes known as the Kuttuvans. However the regions south of the Pamba River was ruled by the Ay kingdom during the ancient period. Pamba is mentioned as Baris in the ancient Greco-Roman travelogues. There are archaeological evidences of the early period of this district, including ancient fossils, stone inscriptions and monuments, in the archeological sites like the excavation sites, the caves, the temples, etc. The literary works of the Sangam period also help to take a look into the ancient period of the district. Alappuzha district was once a prominent centre of Buddhism in South India prior to the arrival of Nambudiri Brahmins into the region. Sri Mulavasam was then a prominent Buddhist pilgrimage centre in the Indian peninsula. Numerous remnants of once flourished Buddhism have been found from the taluks of Ambalappuzha and Mavelikara. Medieval history The regions included in the district had a prominent position in the medieval Malayalam literary works such as Unnuneeli Sandesam. One among the famous literary works of this period was the Ascharya Choodamani, a Sanskrit drama written by Sakthibhadra who was a scholar from Chengannur. The feudal monarch of Chempakasseri was at its zenith during the reign of Pooradam Thirunal Devanarayanan, a great scholar and a poet who was also the author of the literary work Vedantha Ratnamala. It is said that Ambalappuzha Sri Krishna Temple, at Ambalappuzha, was constructed and the idol of Lord Krishna installed during that time. Chempakassery was ruled by Brahmin monarchs during the medieval period. It is believed that Melpathur Narayana Bhattathiri, Kumaran Namboothiri, and Neelakanta Deekshithar were eminent scholars who patronized his court. Feudal principalities during the medieval period The southern regions of the modern-day Alappuzha district once formed part of the erstwhile "kingdom of Odanad" (also known as the "kingdom of Kayamkulam" or known by the name "Onattukara"), which was later invaded by the Travancorean forces in the year 1746. It was a branch of the ancient Ay kingdom. It was also known as the Chirava Swaroopam, where the word Chirava derives from the combination of two Malayalam