In the then following description of the 9th and 10th century, Deschner illustrates the deep entanglement of secular and church power. Clerical principalities came into existence and the military service of the high clergy prospered. Under the Ottonian dynasty, the Church in the Holy Roman Empire was completely militarised; dioceses and abbeys controlled a major military potential. Even popes entered wars: Leo IV in the naval Battle of Ostia (849) and John X in the Battle of Garigliano (915). Popes excommunicated each other, some were thrown in prison, strangled, mutilated, poisoned. Sergius III had even two other popes murdered. Chapter 3 discusses the Pseudo-Isidorian Decretals, which are the most important forgery in Carolingian times (Dawson).