Polonnaruwa bears witness to several civilizations, notably that of the conquering Cholas, disciples of Brahminism, and that of the Sinhalese sovereigns during the 12th and 13th centuries. This immense capital created by the megalomaniac sovereign, Parakramabahu I, in the 12th century, is one of history's most astonishing urban creations, both because of its unusual dimensions and because of the very special relationship of its buildings with the natural setting. It is also a shrine of Buddhism and of Sinhalese history. The tooth of the Lord Buddha, a remarkable relic placed in the Atadage under Vijabayahu, was considered as the talisman of the Sinhalese monarchy: its removal by Bhuvanaikabahu II confirmed the decline of Polonnaruwa.

After the destruction of Anuradhapura in 993 by Rajaraja, Polonnaruwa, a temporary royal residence during the 8th century, became the capital. The conquering Cholas constructed monuments to their religion (Brahmnism), and especially temples to Shiva where fine bronze statues, today in the Museum of Colombo, were found. The reconquest of Ceylon by Vijayabahu I did not put an end to the city's role as capital: it became covered, after 1070, with Buddhist sanctuaries, of which the Atadage (Temple of the Tooth Relic) is the most renowned.

The apogee of Polonnaruwa occurred in the 12th century AD. Two sovereigns then proceeded to endow it with monuments. Parakramabahu I (1153-86) created within a triple-walled enceinte a fabulous garden-city, where palaces and sanctuaries prolonged the enchantment of the countryside. The following monuments date from this reign: the Lankatilaka, an enormous brick structure which has preserved a colossal image of Buddha; the Gal Vihara, with its gigantic rock sculptures which may be placed among the chefs-d'ouvre of Sinhalese art; the Tivanka Pilimage, where wall paintings of the 13th century illustrate the jataka (narratives of the previous lives of Buddha), etc. Nissamkamalla hastily constructed monuments that, although less refined than those of Parakramabahu I, were nonetheless splendid: the Rankot Vihara, an enormous stupa 175 m in diameter and 55 m high, is one of the most impressive; its plan and its dimensions are reminiscent of the dagabas at Anuradhapura.

After this golden age, Polonnaruwa underwent a century of difficulties, before its final decline. The city which was invaded by the Tamils and the Maghas, then reconquered in a precarious manner, was only periodically the capital before the end of the 13th century when it was captured in an assault by Bhuvanaikabuha II, who set up his government at Kurunegala.