After the battle of the White Mountain, the interest of the story of Prague declines for a time. A period of strenuous reaction in Church and State, during which the Government endeavours to efface the memorials of past national glory, cannot be picturesque. As it was necessary to replace by new architectural monuments the ancient buildings that recalled events that it was now thought desirable to forget, Prague was in the seventeenth and eighteenth century covered with buildings in the rococo and 'Jesuite' styles, which often unfavourably impress the passing traveller who is unable to discern that they are by no means connected with the period of Bohemia's greatness. During the Thirty Years' War Prague several times again plays a considerable part. After Gustavus Adolphus's great victory at Breitenfeld in 1831, his Saxon allies occupied Prague in November of that year. They were accompanied by many Bohemian exiles, who caused the heads of the twelve patriots that were still exposed on the bridge towers to be removed and buried with great solemnity in the Tyn Church. Preparations were even made to re-establish Protestantism, but in May of the following year Wallenstein's army stormed the Malá Strana and the Hradcany Castle, and the Saxons shortly afterwards entirely evacuated Bohemia, though not before amassing [Illustration: THE OLD SYNAGOGUE] a large amount of plunder. Many of the treasures of Rudolph's collections in the Hradcany Castle thus found their way to Dresden. In 1648 Prague was the scene of the last struggles of the war that had begun there thirty years before. A Swedish force, under General Königsmark, entered Bohemia in that year and advanced rapidly on Prague. Negotiations for peace had begun in the previous year, and it has been often wondered why this last Swedish incursion took place. Bohemian writers have surmised that the desire for plunder, and particularly the attraction of Rudolph's far-famed collections, were partly the motive. The Swedes obtained possession of the part of Prague that lies on the left bank of the river through the treachery of Otowalsky, an Imperial officer who had been dismissed from the service. He informed the Swedes that the walls of the Malá Strana were under repair, and that there was therefore a temporary gap in them. In the night of July 26 the Swedish troops entered the town by this gap, opened the Strahov gate and seized the Malá Strana and the Hradcany. The Swedes were, however, unable to obtain possession of the part of the town on the right bank of the Vltava, even after a second Swedish army had joined them in October. The citizens, now mostly Catholics, headed by Jesuit monks, bravely defended the bridge of Prague, and the Jewish colony, always a considerable one at Prague, also bravely took part in the defence. On November 3, the news of the conclusion of the Treaty of Westphalia reached Prague and put a stop to hostilities.