The second most ancient of Sri Lanka's kingdoms, Polonnaruwa was first declared the capital city by King Vijayabahu I, who defeated the Chola invaders in 1070 CE to reunite the country once more under a local leader. While Vijayabahu's victory and shifting of Kingdoms to the more strategic Polonnaruwa is considered significant, the real Polonnaruwa Hero of the history books is actually his grandson, Parakramabahu I. The city Polonnaruwa was also called Jananathamangalam during the short Chola reign.
It was his reign that is considered the Golden Age of Polonnaruwa, when trade and agriculture flourished under the patronage of the King, who was adamant that no drop of water falling from the heavens was to be wasted, and each be used toward the development of the land; hence, irrigation systems far superior to those of the Anuradhapura Age were constructed during Parakramabahu's reign, systems which to this day supply the water necessary for paddy cultivation during the scorching dry season in the east of the country.

The greatest of these systems, of course is the Parakrama Samudraya or the Sea of Parakrama, a tank so vast that it is often mistaken for the ocean. It is of such a width that it is impossible to stand upon one shore and view the other side, and it encircles the main city like a ribbon, being both a defensive border against intruders and the lifeline of the people in times of peace. The Kingdom of Polonnaruwa was completely self-sufficient during King Parakramabahu's reign.

However, with the exception of his immediate successor, Nissankamalla I, all other monarchs of Polonnaruwa, were slightly weak-willed and rather prone to picking fights within their own court. They also went on to form more intimiate matrimonial alliances with stronger South Indian Kingdoms, until these matrimonial links superseded the local royal lineage and gave rise to the Kalinga invasion by King Magha in 1214 and the eventual passing of power into the hands of a Pandyan King following the Arya Chakrawarthi invasion of Sri Lanka in 1284. The capital was then shifted to Dambadeniya.

Today the ancient city of Polonnaruwa remains one of the best planned Archeological relic sites in the country, standing testimony to the discipline and greatness of the Kingdom's first rulers. Its beauty was also used as a backdrop to filmed scenes for the Duran Duran music video Save a Prayer in 1982.

The ancient city of Polonnaruwa has been declared a World Heritage site by UNESCO.

Polonnnaruwa, 216 km from Colombo, was the capital of Sri Lanka during the medieval period (11c - 13c). Anuradhapura remained as capital for about 15 centuries. With the growth of South Indian Empires and frequent invasions by them, Anuradhapura was no longer safe as the Capital of the Sinhala Kings. It was because of this that Capitals started moving to the south. The first capital after Anuradhapura was Polonnaruwa. After a few centuries capitals started to move further southward. Capitals changed from one city to another very fast. Sri Lankan historians call this the 'southward drift'- shifting of capitals to the south of Sri Lanka. Polonnaruwa remained as the capital of Sri Lanka for the longest period during this post Anuradhapura era. While a large number of the places of historical and archeological interest are scattered over a very wide area at Anuradhapura, at Polonnaruwa a large number of such places are found within a very small locality.