The Sword-Brothers were established in 1202 in Riga to conquer and convert pagan Baltic tribes to Christianity. By the 1230s under the leadership of Master Volkwin, the Order was coping with strained financial resources, decreasing manpower, and ill reputation. The Order was in conflict with the papacy under Pope Gregory IX and the Holy Roman Emperor, two of its biggest supporters, over Estonia. However, on 19 February 1236, Pope Gregory IX issued a papal bull declaring a crusade against Lithuania. Volkwin was reluctant to launch offensive actions against Lithuanian lands. His reluctance was determined by understanding that the Order lacked strength to wage war against the Lithuanians. The lack of strength was a result of interior conflicts with the Bishopric of Riga. Besides that, the Livonian Sword Brothers had still little knowledge of the lands lying south to the Order's territory. Volkwin delayed starting military actions for an entire summer, hoping to escape a risky operation into unexplored lands. However, the insistence of Pope Gregory IX forced him to lead a new campaign. Volkwin targeted Samogitia, planning to conquer the coast of the Baltic Sea and connect with the Teutonic Knights in Prussia. The Sword-Brothers wanted to keep expanding along the Daugava River and was somewhat reluctant to march against Samogitia. In fall of 1236 a party of crusaders from Holstein arrived in Riga; it demanded to be led into a battle. Volkwin gathered a large war party, which included troops from Pskov Republic, Livonians, Latgallians, Curonians, Estonians.
Events of the battle
Crossing the lands of Semigallians, which were not in the Order's control, the crusaders marched southward into Samogitia, raiding and plundering local settlements. The locals had only a few days to gather troops for defense. On the knights' northward return, however, they encountered a determined group of Samogitians at a river crossing. Unwilling to risk losing their horses in the swampland, the Holsteiners refused to fight on foot, forcing the knights to camp for the night. The next morning, on the day of Saint Maurice, the main pagan forces, possibly led by Duke Vykintas, arrived at the camp. The Lithuanian light cavalry flung javelins at short range, which were highly effective against the unwieldy Livonian heavy cavalry. The swampy terrain was advantageous for the lightly armed pagans. The slaughter of the Christian troops, including Volkwin, sowed the seeds of confusion in the Livonian ranks. The lightly armed native forces under the command of the Brothers soon fled from the battle. The baptized Curonians betrayed the crusaders, attacking them from rear. Almost all members of the Order, including Volkwin, died in the battle. Those crusaders and knights who tried to flee to Riga were allegedly killed by the Semigallians. Only every tenth Crusader reached Riga.
Location
The exact location where the battle took place is unknown. The Chronicum Livoniae by Hermann de Wartberge mentioned that the battle was fought in terram Sauleorum. Traditionally, this was identified with Šiauliai in Lithuania or with the small town of Vecsaule near Bauska in what is today southern Latvia. In 1965 the German historian Friedrich Benninghoven proposed Jauniūnai village in Joniškis district, Lithuania as the battle site. The theory gained some academic support and in 2010 the Lithuanian government sponsored construction of the memorial in Jauniūnai – a tall sundial, a pond, and a park of oaks. The village of Pamūšis, situated some east of Janiūnai on the Mūša River, also claims to be the location of the battle. Saule/Saulė means "the Sun" in both Latvian and Lithuanian.
