The Sri Lankan monarch most closely associated with Polonnaruwa is Parakramabahu I (reigned 1153–86), or Parakramabahu the Great, as he’s often styled, the last in the sequence of famous Sinhalese warrior kings, stretching back to the legendary Dutugemunu, who succeeded in uniting the entire island under the rule of a single native monarch.
Parakramabahu (a grandson of Vijayabahu) was born at Dedigama, capital of the minor kingdom of Dakkinadesa, which was ruled by his father. Upon becoming ruler of Dakkinadesa, Parakramabahu established a new capital at Panduwas Nuwara before launching a campaign against the king of Polonnaruwa, his cousin Gajabahu. After an extended series of military and political manoeuvrings, Parakramabahu finally triumphed and was crowned king of Polonnaruwa in 1153, although it took a brutal and protracted series of military campaigns before the entire island was finally subdued.
Even while Parakramabahu was mopping up the last pockets of resistance in the south, he began to embark on the gargantuan programme of building works and administrative reforms which transformed Polonnaruwa into one of the great cities of its age, as well as finding the time to launch a couple of rare military offensives overseas, first in Burma and then India. According to the Culavamsa, the new king built or restored over six thousand tanks and canals, including the vast new Parakrama Samudra in Polonnaruwa, as well as restoring the three great dagobas at Anuradhapura and rebuilding the monastery at Mihintale. It was at his new capital, however, that Parakramabahu lavished his greatest efforts, supervising the construction of a spate of imposing new edifices including the Royal Palace complex, the majestic Lankatilake, and the beautiful Vatadage, the crowning achievement of medieval Sinhalese architecture.