Jadwiga of Poland
It is not entirely clear why diplomatic talks between Jogaila and the Order broke down. Some suggested that Jogaila already knew about the opportunity to marry Jadwiga of Poland and become Polish King. Others argued that Uliana, mother of Jogaila, disapproved of baptism in the Catholic rite as she was an Orthodox. Yet others pointed to Masovia where tensions rose as Jogaila started a war against Siemowit IV, who supported Vytautas and was friendly with the Order, and the Order's attempt to play Vytautas against Jogaila.