ENThis book aims to present a broad perspective of the relations between The Polish-Lithuanian Commonwealth and Hussite Bohemia in 1420-1433. The hitherto existing historical deliberations have also been critically discussed in this monograph. So far historians have tended to see the political activities of these two countries, Poland and Lithuania, as linked by a dynastie union that is commonly and fully coordinated. According to this concept there were no significant differences between king Władysław Jagiełło (Jogaila) of Poland and duke Witold (Vytautas) of Lithuania. The relationship between these two figures was affected by proposal made by the Bohemian Hussites to the Polish ruler offering him the Bohemian crown. King Władysław refused the offer, but secretly he supported the actions of the grand duke of Lithuania and his governor in Bohemia - Sigmund Korybutowicz. [...].