The protracted struggle known as the Thirty Years' War was most prejudicial to the interests of the Rhine valley, which was overrun by the troops of the several nationalities engaged. One phase of this most disastrous struggle--the War of the Palatinate--carried the rapine and slaughter to the banks of the Rhine, where, as has been said, they were long remembered. During the reign of Ferdinand III (1637-1659) a vigorous and protracted war broke out between France and Germany, the former assisted by her ally Sweden. Germany, seeing that unless peace were restored her ruin as a great power would be inevitable, entered into negotiations with France, and in 1648 the claims of France and Sweden were settled by the Peace of Westphalia. This treaty is particularly notable in the present instance because it gave to the former country the footing on the Rhine already mentioned as the beginning of French encroachments. Germany was forced to give up Alsace, on the left bank of the river. France, by the seizure of Strassburg, confirmed by the Treaty of Ryswick in 1695, extended her boundaries to the Rhine. At the beginning of the French Revolution Leopold II of Germany and other German monarchs agreed to support the cause of French royalty, a resolution which was disastrous to the Empire. In 1795 Prussia, for political reasons, withdrew from the struggle, ceding to France, in the terms of the Treaty of Basel, all her possessions on the left bank of the Rhine. In 1799 war again broke out; but in 1801 the Treaty of Luneville gave to France the whole of the left bank of the river. Thus the historic stream became the boundary between France and Germany. In 1806 the humiliation of the latter country was complete, for in that year a number of German princes joined the Confederation of the Rhine, thus allying themselves with France and repudiating their allegiance to the Empire. In 1815, at the Congress of Vienna, the whole of the Lower Rhenish district was restored to Prussia, while Bavaria, a separate state, was put in possession of the greater part of the Palatinate on the left bank of the Rhine. From that time onward the German national spirit flourished, but the future of the Empire was uncertain till its fate was decided by the Franco-Prussian War of 1870-71. In the great hall of the Palace of Versailles in 1871 William I, King of Prussia, proclaimed, in the hour of victory, the restoration of the confederated German Empire. The French forfeited their Rhenish provinces, and once more the Rhine was restored to Germany. That the Thirty Years' War did not fail to linger in the folk-memory is evidenced by the following gruesome legend of Oppenheim: The Battle of Skeletons