With papal approval and encouragement, King Władysław I of Poland allied with Gediminas of Lithuania and organized the raid against Louis V of Germany.
[3] Pope John XXII opposed Louis' ambitions to become the Holy Roman Emperor, King Władysław regarded Neumark (East Brandenburg) as Polish territory, while Lithuanians sought loot.
After the death of Henry VII, Holy Roman Emperor, in August 1313, a war erupted between cousins Louis V of Germany and Frederick the Fair of Austria for the imperial crown.
[11] Seeing a potential new ally, the Pope sent a delegation to Lithuania and by threat of excommunication compelled the Teutonic Knights, who supported Louis V of Germany, to make peace with Gediminas in August 1324.
[13] On February 7, 1326, with the help of papal legates, Władysław I concluded an armistice at Łęczyca[3] with the Teutonic Knights and three Masovian dukes which guaranteed safe passage for the Lithuanian troops through Prussia and Masovia while they were in "Polish service".
[1] The truce was to last to Christmas 1326 and, according to chronicler Detmar von Lübeck, papal legates even accompanied the army to ensure the Knights observed the armistice.
[7] Reportedly distraught by Lithuanian cruelty,[16] Masurian nobleman Andrew Gost ambushed and killed David of Hrodna and their way back to Lithuania.