The Teutonic Order first responded to a request from Konrad I of Masovia for assistance against pagan Prussians in 1228. Over the following decades, with the assistance of regular crusades, they conquered the Prussians and attacked the Lithuanians. The Order purchased Brandenburg from Władysław I Łokietek in compensation for the military services they had provided Poland, and in 1309 the grand master transferred his headquarters to Prussia creating a unique state. The state's chief rivals were the Kingdom of Poland and the Archbishopric of Riga. The order refused cooperation with the local papal legates and concentrated on influence at the papal court. The grand masters looked for alliances, including with John of Bohemia, and recruited French, Burgundian, Dutch, English, and Scottish knights for raids called "reysen". These were exemplars of chivalric values and nobility. Historians see the battle of Tannenberg in 1410 as the turning point. The Order's defeat was surprising and catastrophic; it was only by systematically destroying all available food in the 1414 Hunger War that the Poles and Lithuanians were repulsed. In 1435 the Livonian branch of the Teutonic Order suffered defeat at the battle of the Swienta River but in 1502 invaded Russia gaining half a century of peace. During the Reformation, Prussia became Protestant and in 1560, after defeat by the Russians at the Ermes, the order secularised. Its territories were divided. Changing priorities caused the failure of the Baltic Crusades. Crusading was no longer seen as a method of earning salvation or effective in the wars waged in the Baltic.