Shivagrha inscription

The Shivagrha inscription is an inscription from the Medang Kingdom of Central Java, dated in "chandrasengkala" (chronogram) "”Wwalung Gunung sang wiku”", that is, the year 856 CE (or 778 in the native Saka Calendar). The inscription was inscribed by order of Dyah Lokapala (Rakai Kayuwangi) right after the end of Rakai Pikatan's reign, and gave a detailed description of a grand temple compound dedicated to Shiva called "Shivagrha" ("the House of Shiva"), corresponding to the Prambanan temple compound. 
A public water project to change the course of a river near Shivagrha Temple is also mentioned in this inscription. The river, identified as the Opak River, now runs north to south on the western side of the Prambanan temple compound. Historians suggest that originally the river was curved further to east and was deemed too near to the main temple. The project was done by cutting the river along a north to south axis along the outer wall of the Shivagrha Temple compound. The former river course was filled in and made level to create a wider space for the temple expansion, the space for rows of "pervara" (complementary) temples. 
Also mentioned is that the King (Pikatan) was a Shivaist, in contrast to his queen consort Pramodhawardhani, who was a Buddhist. The inscription mentions a battle for royal succession against Jatiningrat (Rakai Pikatan), the rebel having made a fortress of hundreds of stones for refuge. This fortress are connected to the site of Ratu Boko. Traditionally Balaputradewa was thought as the person that led the war against Pikatan. However, this theory was revisited as it was more likely that it was Rakai Walaing pu Kumbayoni that challenged Pikatan authority as the new monarch of Medang Mataram kingdom. Rakai Walaing was a powerful landlord that claimed to be the descendants of king that once ruled Java.
Today the inscription is displayed in the National Museum of Indonesia, Jakarta, under the inventory number No. D.28.