Bosch in his book "Srivijaya, de Sailendravamsa en de Sanjayavamsa" (1952) suggested that king Sanjaya was the progenitor of the Sanjaya Dynasty, and there was two dynasties that ruled Central Java; the Buddhist Sailendra and the Shivaist Sanjaya dynasty [REF].
The prevailing historical interpretation holds that the Sailendra dynasty co-existed next to the Sanjaya dynasty in Central Java, and much of the period was characterised by peaceful co-operation.