224 THE LATER xMIDDLE AGES determination of a prince, known as Henry the Navigator, despatched expedition after expedition, which explored the eastern coast of Africa, and prepared the way for the great voyagers, who at the end of the century found their way round the Cape of Good Hope, and set up a maritime empire in the eastern seas. On the east of Bohemia, and of the German border, lay the kingdom of Poland. Between Poland and the Baltic Sea, and 5. North along the eastern shores of the Baltic, lay the and East. province or sovereignty of the Teutonic Knights. On the east of the Knights was the duchy of Lithuania, the last region in Europe to adopt Christianity. Beyond these were the Russian provinces, which, ever since the coming of the Tartar hordes, had remained subject to the Mongol dominion. There is no need to follow closely the story of these northern states at this stage, but we must note the position which had been reached in the fifteenth century. Poland may be said to have begun to rank as a Power under a very able monarch, Casimir, during the middle period of the fourteenth century. On his death his nephew, King Lewis of Hungary, became King of Poland. King Lewis had two daughters. The one, Mary, succeeded to the Hungarian Crown and married Sigismund, afterwards German Emperor ; Poland, choosing that the Crowns should be separate, took for queen the other daughter Hedwig. Hedwig married the Grand Duke of Lithuania, Jagellon, and thus began the Jagellon dynasty. The marriage made it necessary for Jagellon and his people to adopt Christianity. The Christianising of Lithuania left the Teutonic Knights without any particular justi- fication for their existence. In a few years' time the now powerful Polish kingdom had taken possession of much of their inheritance. Although the Jagellons held the Crown in succession for a couple of centuries, the monarchy was in form elective ; and we periodically find both Hungary and Bohemia electing a King of Poland to their respective thrones, until both were secured by the Hapsburgs. Poland also extended her dominions eastwards over a considerable part of the Russian territory. It is important to bear in mind, with regard to
