Poland's fatal mistake: how it missed its chance to annex Ducal Prussia

Poland had several opportunities to incorporate Ducal Prussia into the Crown, which could have permanently neutralised the Hohenzollern threat. Instead, successive rulers made concessions and focused on wars with Sweden and Muscovy. Historians Andrzej Chwalba and Wojciech Harpula examine whether a different choice could have fundamentally altered the histories of both Poland and Germany.