Medang Empire, sometimes referred to as Mataram, was an Indianized kingdom based in Central Java around modern-day Yogyakarta between the 8th and 10th centuries. The kingdom was ruled by the Sailendra dynasty, and later by the Sanjaya dynasty. The centre of the kingdom was moved from central Java to East Java by Mpu Sindok. An eruption of the volcano Mount Merapi in 929, and political pressure from Sailendrans based in the Srivijaya Empire may have caused the move.