The inscription is engraved on an oblong slab, called gal-pota (‘stone-book’), which lies close to the eastern outer wall of the so-called Häṭa-dā-gē, ‘the Shrine of Sixty Relics’, at Poḷonnaruva. Consisting of seventy-two lines and more than 4,300 letters, the inscription is the longest known in Sri Lanka. It was created during the reign of Niśśanka Malla (1187-1196 A.D.) but no specific date is given in the text. The contents of the inscription record the great actions of Niśśanka Malla. Wickremasinghe interprets the text as part of an broader political strategy in which the king commissioned numerous inscriptions extolling his good deeds in a bid to present himself as a sovereign who held his authority entirely for the good of the community, thereby winning the confidence of his subjects and securing his claim to the throne. Niśśanka Malla appears to have been the first Sri Lankan monarch to employ such a strategy. The galpota inscription contains an important exposition of his political theory of kingship.
The galpota is aligned north-south and measures more than eight metres long. It was raised on a brick podium sheltered by a canopy supported on ten pillars. Both sides and ends of the slab are ornamented by double bands of haṁsas moving from left to right. At the middle of each end is a seated figure of Lakṣmī holding flowers, upon which a pair of elephants pour water from a chatty. The surface of the slab is divided into three partitions, each of which contains a portion of the inscription, starting from the first line at the top left-hand (south-west) corner of the stone slab. These partitions are designed to be read separately. The third partition is damaged, rendering some parts of the inscription illegible. A postscript on the vertical face of the southern end of the slab tells us that this stone was brought for the special purpose of engraving the present record from Sǟgiriya (Mihintale) by the mighty men of Niśśaṅka-Malla. This would imply that the slab was transported upwards of eighty miles. However, Wickremasinghe and others have suggested that the stone was in fact sourced from Sigiriya, only 15 miles distant, rather than Sǟgiriya.