The Kingdom of Polonnaruwa was the kingdom from which Sri Lankan kings ruled the island from the 11th century until 1310 CE. Pollonnaruwa was the fifth administrative center of Rajarata.
The city is situated on the left bank of River Mahaweli. Archeological evidence and accounts in chronicles suggests that the city is as old as Anuradhapura. The Vijithagama settlement made by Vijitha in 400 BCE is thought to be situated near the town.
Name Pulathisipura is derived from the guardian sage of the city Pulasthi there are several theories on the name Polonnaruwa. According to the most accepted one word is derived from conjunction of to words Pulun which means cotton in sinhala and Maruwa which mean exchanging.So Pulun+Maruwa=Polonnaruwa.
After ruling the country for over 1,200 years from the Kingdom of Anuradhapura, in 1017, Chola King Rajarajan I captured Anuradhapura and took King Mahinda V as a captive to India where Mahinda V would die in 1029. Cholas shifted the capital to Polonnaruwa and ruled Sri Lanka for 52 years. Polonnaruwa was named as Jananathamangalam by the Cholas. King Vijayabahu I defeated Cholas and regained the Sinhalese lineage. Polonnaruwa had previously been an important settlement in the country, as it commanded the crossings of the Mahaweli Ganga towards Anuradhapura.
Some of the rulers of Polonnaruwa include Vijayabahu I and Parakramabahu I (Parakramabahu the Great). Most of Polonnaruwa that remains today dates from after the 1150s, as the extensive civil wars that preceded Parakramabahu's accession to the throne devastated the city. Parakrama Pandyan II from Pandyan Kingdom invaded the Kingdom of Polonnaruwa in the thirteenth century and ruled from 1212 to 1215 CE. He was succeeded by Kalinga Magha the founder of the Jaffna kingdom. Kalinga Magha ruled 21 years until he was expelled from Polonnaruwa in 1236.
The Kingdom of Polonnaruwa was abandoned in the 14th century, and the seat of government for the Sinhalese kings was moved to Yapahuwa. Although many factors contributed to this, the leading cause of the abandonment of Polonnaruwa as the kingdom of Sri Lanka was its susceptibility to invasions from south India.