The Peace of Westphalia, 1648, marks the end of the Thirty Years' War, and finds Germany with a population reduced from sixteen millions to four millions. Famine which drove men and women to cannibalism, bands of them being caught cooking human bodies in a caldron for food; slaughter that drove men to make laws authorizing every man to have two wives, and punishing men and women who became monks and nuns; lawlessness that bred roving bands of murderers, who killed, robbed, and even ate their victims, demanded a ruler of no little vigor to lead his people back to civic, moral, and material health. The Great Elector wrested east Prussia from Poland, he defeated and drove off the Swedes, whom Louis XIV had drawn into an alliance against him, he travelled from end to end of his country, seeking out the problems of distress and remedying them by inducing immigration from Holland, Switzerland, and the north, by building roads, bridges, schools, and churches, and by encouraging planting, trade, and commerce. He built the Frederick William Canal connecting the Oder and the Spree, and introduced the potato to his countrymen. Germany now produces in normal years fifteen hundred million bushels of potatoes. The splendid equestrian statue of the Great Elector on the long bridge at Berlin, is a worthy monument to the first great Hohenzollern. When Charles II of Spain died, Louis XIV, the Emperor Leopold I of the Holy Roman Empire, and the Elector of Bavaria, all three claimed the right to name his successor. In the war that followed and which lasted a dozen years, the Emperor, Holland, England, Portugal, the Elector of Hanover, and the Elector Frederick III of Brandenburg, the son of the Great Elector, were allied against France. Frederick, the Elector of Brandenburg, was permitted by the Emperor, in return for his services at this time, to assume the title of King, and he crowned himself and his wife Sophia Elizabeth, at Koenigsberg, King and Queen of Prussia, taking the title of Frederick I of Prussia, January 18th, 1701.