The story begins with a defeat. In the late tenth century, Chola kings from southern India conquered Anuradhapura, Sri Lanka's ancient capital, and shifted the island's administrative center to Polonnaruwa - a more strategically defensible location in the dry zone interior. For decades, Sinhalese rulers fought to reclaim their sovereignty. King Vijayabahu I finally drove the Cholas out in 1070, establishing the Kingdom of Polonnaruwa and restoring Sinhalese rule over the island. Vijayabahu chose to keep Polonnaruwa as his capital rather than return to Anuradhapura, recognizing its advantages: proximity to the eastern ports, natural defenses, and the agricultural wealth of the surrounding plains fed by ancient irrigation systems.

Parakramabahu I, who reigned from 1153 to 1186, was the kingdom's most ambitious ruler. He unified the entire island under one crown for the first time - no small feat in a land where regional lords had long maintained semi-independent power. Then he looked beyond Sri Lanka's shores. His armies intervened in a civil war in the Pandya country of southern India, seizing Pandya Nadu and establishing military administration alongside the allied Vira Pandyan. His currency, the Kahapana, was struck in Indian territories. Rameshwaram came under joint Sinhalese and Pandyan rule. But the expansion overreached. The Chola empire struck back, and by 1182, Polonnaruwa's forces had been driven from the Indian mainland - Chola records describe Sinhalese soldiers fleeing into the sea. The overseas adventure ended in humiliation, though the domestic achievements endured.

Parakramabahu's greatest legacy was not military but hydraulic. The Parakrama Samudra - the Sea of Parakrama - is one of the largest ancient reservoirs in the world, an engineering project that transformed the dry zone landscape into productive farmland. The kingdom's wealth flowed from these irrigation works, which supported the rice agriculture that fed a sophisticated urban civilization. Polonnaruwa itself became a city of remarkable architecture: the Vatadage, a circular relic house of extraordinary stone carving; the Gal Vihara, where four enormous Buddha figures were carved from a single granite face; the Lankatilaka, a towering brick temple. The artistic and architectural achievements of the Polonnaruwa period represent a high point in Sri Lankan civilization.

The kingdom did not die in a single blow but unraveled over decades. After Parakramabahu I, the royal court descended into factional warfare - competing claimants backed by Pandyan and Kalinga factions tore at the fabric of centralized rule. Nissanka Malla, who reigned from 1187 to 1196, attempted to revive the kingdom's grandeur, but his successors lacked the capacity to hold it together. In 1215, Kalinga Magha, an invader from the Eastern Ganga Dynasty, captured Polonnaruwa. His reign was brutal enough to drive the Sinhalese court southward, abandoning the dry zone capitals permanently. The great city fell silent. Jungle reclaimed the reservoirs and temples. It was not until British-era archaeologists arrived in the nineteenth century that the scale of what had been built - and lost - began to emerge from the undergrowth.