 Complete the following phrase:  Later in the ninth century, during the reign of Boris I, the pagan temples in Pliska likely began to be converted to Christian churches. In 886, Boris founded the Pliska Literary School which was moved to Preslav when Boris later relocated the capital. When Boris fell seriously ill and retired to a monastery, his son Vladimir succeeded him and attempted to reestablish paganism. During this period 889-93 the large stone basilica at Pliska built under Boris was heavily damaged. Boris left his monastery to overthrow his son, and after succeeding, relocated the capital to the nearby town of Preslav which seems to have been a centre of Christianity in the state. Following this Pliskas relevance in Bulgar goverce steadily declined until the Bulgarian state was destroyed by the Byzantine general turned emperor when he murdered the previous emperor Nikephoros Phokas John Tzimiskes. He defeated the Russian forces 