a decisive battle forcing them to surrender. In 1265 reinforcements arrived from Germany: armies of Duke Albrecht of Braunschweig and Margrave Albert of Meissen arrived in Prussia, but were unable to achieve much. In 1266 Otto III and John I, co-rulers of Brandenburg, built a castle in the Natangian lands between Balga and Königsberg and named it Brandenburg (since 1945 Ushakovo). Due to bad weather they did not organize campaigns into Prussian lands. When the Dukes returned home, Brandenburg was captured by Glappe and his Warmians. The very next year Otto returned to rebuild the castle. Both John and Otto died before the end of 1267, and Otto's son was killed in a tournament. Subsequent Dukes of Brandenburg were not as supportive of the Knights. In 1266 Duke Swantopolk, the supporter of the Prussians during the First Uprising, died and his sons Mestwin and Warcisław briefly joined the Prussians in the uprising. In 1267 King Ottokar II of Bohemia, who already participated in the Prussian Crusade in 1254 and who was promised by Pope Urban IV all Prussian lands he could conquer, finally arrived in Prussia. His only achievement was forcing Duke Mestwin to reconcile with the Teutonic Knights. His large army was unable to campaign due to an early thaw: heavily armed knights could hardly fight during the wet and swampy spring season. The warfare with the Prussians relied on guerilla raids in the border regions. Small groups of men, a dozen to a hundred, made quick raids on farms, villages, border posts, etc. This was a positional warfare where neither side could defeat the other, but the Teutonic Knights relied on future reinforcements from Germany and Europe, while Prussians were draining their local resources. After the massacre of surrendered Teutonic soldiers in the Battle of Krücken in 1249, the Knights refused to negotiate with the Prussians. The Prussians were also unable to coordinate their efforts and develop a common strategy: while each clan had its own leader, there was no single leader of all the clans. The Natangians had to watch for attacks from Balga, Brandenburg, Wehlau, and Königsberg while the Warmians were threatened by garrisons at Christburg and Elbing. This way only Diwane and his Bartians were able to continue the war in the west. They made several minor expeditions to Culmerland each year. The end of the uprising The major Prussian offensive was organized in 1271