The inscription is cut into the rock near the ancient Buddhist monastery situated on the low, rocky hill by the Meddeketiya tank at Saṁgamuva, a village about two miles to the north-east of Gokarälla, in the Häḍahaya Kōraḷē of the Kuruṇǟgala District. A series of over one hundred steps, cut into the bare side of the rock, lead up the side of the hill to a plateau, upon which stand the ruins of an old stupa and other monastic buildings. The inscription is engraved at the top of the steps, to the left as one ascends the hill. It was copied for the first time by Senarath Paranavitana in 1931 (see Archaeological Survey of Ceylon Annual Report for 1930–31, p. 5). The text is written in Sinhalese, apart from the last four lines, which consist of a Sanskrit verse in the Vasantatilakā metre, though nearly half of this verse is no longer legible.
The inscription is of exceptional historical importance, since it records an alliance between two princes called Gajabāhu and Parākramabāhu, who can be identified as Gajabāhu II (r. 1131–1153) and the future Parākramabāhu I (r. 1153–1186). The Mahāvaṁsa records how Parākramabāhu, after consolidating his position in the principality of the Dakkhiṇadesa to which he succeeded on the death of his uncle Kittisirimegha, undertook a campaign against his cousin Gajabāhu II with the object of making himself ruler of the island of Sri Lanka. Eventually, the two princes came to a peace settlement, as recorded in the present inscription. The two princes speak in the first person in this inscription. After introducing themselves by name, they come to the matter of the agreement. The first clause states that they will not wage war against each other for the rest of their lives. Although now partly damaged, the second clause seems to declare that, whichever prince dies first, his possessions will pass to the surviving prince. Since Gajabāhu was by some margin the older of the two, this clause essentially amounts to him bequeathing his kingdom to Parākramabāhu. The third clause is now almost completely illegible. By the fourth and final clause of the treaty, the two princes enter into an offensive and defensive alliance, declaring that any king who is an enemy of one of them, is an enemy of both. Paranavitana interpreted this clause as being directed against Mānābharaṇa, the ruler of Rohaṇa, who also had designs on Gajabāhu’s throne. The agreement concludes with imprecations against both princes if they act contrary to its terms. It is not clear why this record was engraved at the Saṁgamu Vihāra. Although it was within the territories under Parākramabāhu’s rule, there is nothing to prove that the place was close to his residence, even temporarily. Paranavitana posited that the treaty may have been brokered by a monk who resided at the vihara but this is only conjecture.