Kedu Plain in the context of Sailendra Dynasty

The Shailendra dynasty (IAST: Śailēndra, Indonesian pronunciation: [ʃaɪlenˈdraː] derived from Sanskrit combined words Śaila and Indra, meaning "King of the Mountain", also spelled Sailendra, Syailendra or Selendra) was the name of a notable Indianised dynasty that emerged in 8th-century Java, whose reign signified a cultural renaissance in the region. The Shailendras were active promoters of Mahayana Buddhism and covered the Kedu Plain of Central Java with Buddhist monuments, one of which is the colossal stupa of Borobudur, now a UNESCO World Heritage Site.

The Shailendras are considered to have been a thalassocracy and ruled vast swathes of maritime Southeast Asia; however, they also relied on agricultural pursuits, by way of intensive rice cultivation on the Kedu Plain of Central Java. The dynasty appeared to be the ruling family of the Mataram kingdom of Central Java, and for some period, the Srivijaya Kingdom in Sumatra.

Sanjaya (Sanskrit: सञ्जय, romanized: sañjaya, lit. 'conquest, victory, triumphant'; 716 AD – 746) was the founder of the Mataram kingdom during the 8th century. His name was carved in the Sanskrit Canggal inscription which was found at the Gunung Wukir temple that stood on Wukir or Ukir hill (about 340 m (1,120 ft) high) on the southern Kedu Plain in Central Java.

Another recorded source of Sanjaya's history and his successors is found in the Balitung charter and the Wanua Tengah III inscription. In the Mantyasih inscription, King Balitung mentions what is called 'the builders of keraton', starting from Rakai Mataram (Sanjaya) and followed successively by Maharaja Rakai Panangkaran, Panunggalan, Warak, Garung, Rakai Pikatan, Kayuwangi, Watuhumalang and Watukura (which is Balitung himself). Several inscriptions of Balitung's successor, Daksha, used a dating system based on the year of Sanjaya's accession, which L.C. Damais has calculated as 638 Śaka (716 AD).