A yet more significant change followed. The old tongue of the Church was now to be disused in public worship. The universal use of Latin had marked the Catholic and European character of the older religion: the use of English marked the strictly national and local character of the new system. In the spring of 1548 a common Communion Service in English was added to the solitary Mass of the priest; an English book of Common Prayer, the Liturgy which with slight alterations is still used in the Church of England, soon replaced the Missal and Breviary from which its contents are mainly drawn. The name "Common Prayer," which was given to the new Liturgy, marked its real import. The theory of worship which prevailed through Mediaeval Christendom, the belief that the worshipper assisted only at rites wrought for him by priestly hands, at a sacrifice wrought through priestly intervention, at the offering of prayer and praise by priestly lips, was now set at naught. "The laity," it has been picturesquely said, "were called up into the Chancel." The act of devotion became a "common prayer" of the whole body of worshippers. The Mass became a "communion" of the whole Christian fellowship. The priest was no longer the offerer of a mysterious sacrifice, the mediator between God and the worshipper; he was set on a level with the rest of the Church, and brought down to be the simple mouthpiece of the congregation. [Sidenote: The Triumph of the Emperor.] What gave a wider importance to these measures was their bearing on the general politics of Christendom. The adhesion of England to the Protestant cause came at a moment when Protestantism seemed on the verge of ruin. The confidence of the Lutheran princes in their ability to resist the Emperor had been seen in their refusal of succour from Henry the Eighth. But in the winter of Henry's death the secession of Duke Maurice of Saxony with many of his colleagues from the League of Schmalkald so weakened the Protestant body that Charles was able to put its leaders to the ban of the Empire. Hertford was hardly Protector when the German princes called loudly for aid; but the fifty thousand crowns which were secretly sent by the English Council could scarcely have reached them when in April 1547 Charles surprised their camp at Muhlberg and routed their whole army. The Elector of Saxony was taken prisoner; the Landgrave of Hesse surrendered in despair. His victory left Charles master of the Empire. The jealousy of the Pope indeed at once revived with the Emperor's success, and his recall of the bishops from Trent forced Charles to defer his wider plans for enforcing religious unity; while in Germany itself he was forced to reckon with Duke Maurice and the Protestant princes who had deserted the League of Schmalkald, but whose one object in joining the Emperor had been to provide a check on his after movements. For the moment therefore he was driven to prolong