Around the year 929 CE, the last ruler of the Sañjaya dynasty, King Mpu Sindok of Mataram, moved the seat of power of the Mataram Kingdom from Central Java to East Java and thus established the Isyana dynasty. The exact cause of the move is still uncertain; however, a severe eruption from Mount Merapi or a power struggle with the Sumatra-based Srivijaya kingdom probably caused the move. Historians suggest that some time during the reign of King Wawa of Mataram (924-929 CE), Merapi erupted and devastated the kingdom's capital in Mataram.