He was sent by polish King to negotiate peace treaty with Teutonic Knights and negotiations with King Sigismund von Luxemburg (Sigismund, Holy Roman Emperor) that mediated between parts. On the polish side Mikołaj Błociszewski was negotiating together with Mikołaj Bydgoski, Castellan of Bydgoszcz and Hungarian baron, also from the Clan of Ostoja. On behalf of King Sigismund von Luxemburg the negotiations where led by Stibor of Stiboricz of the Clan of Ostoja. As the negotiations failed, war with the Teutonic Knights had to take place at the Battle of Grunwald (1410).