The leaders of the Lithuanians at that time were the brothers Kynstutt and Olgjerd. Kynstutt was an enemy not to be despised; his restless energy had long kept the Order busy. The heathen army was between thirty and forty thousand strong, and among them were Russian auxiliaries and excellent archers. The Lithuanians carried heavy battle axes, though their principal weapons were the pike and shield, and they also had many horsemen. Notwithstanding their numbers, they were not the equals of the Order in military skill, whether in siege or field. Kynstutt knew this very well and for that reason would not risk battle in the open. He conducted his pillaging expeditions over as wide an area as possible. At one time he would swiftly and suddenly fall upon the Order’s supply trains and slaughter the guards; at others he would burn castles and seek by every means in his power to prevent the building of new ones. He erected castles himself, and as fast as they were destroyed by the knights he would rebuild them. The three most important of these castles were those of Wielun, Pisten, and Kauen. The last was the most remote and was the strongest, being built of stone.