RandomVisitor: Explaining this pun takes several paragraphs from Wikipedia, and the fact that this game features a double-rook endgame. It is unclear whether the pope at the time declared white the new "king" of France:
Castles II: Siege and Conquest
The game Castles 2: Siege and Conquest takes place in a semi-fictionalized version of historical France. The game begins in the year 1312 A.D., shortly before the beginning of the Hundred Years' War. In the game's version of history, France's King Charles dies on the throne in the year 1311. Because Charles left no heirs to take up the crown, it is unclear who will become the new king. The Pope is willing to declare a new King, but only after one of the local nobles has gained significant influence over the land and won favor with the Church.
The player takes the role of one of five different nobles (Albion, Duke of Valois, Anjou, Aragon, or Burgundy), fighting for the title of King of Bretagne. Early on, much of the territory is controlled by local (neutral) lords, and is easily taken up by one of the major players. In addition, three territories are controlled by the Pope, but players may cede additional territories to the Church in order to improve relations.
<The player's task will be to take over as much of France as possible, and then try to claim the throne.> If other players remain at this time, they will attack the player to damage their claim. <Eventually the Pope will decide whether or not to support the claimant, and the game will end.> According to the game manual, the average in-game time passed is usually between three and ten years.
Gameplay includes scouting out unknown territories, conquering them, building castles to prevent revolts and line defenses, raising an army, feeding and paying them, and eventually making a claim for the title of King. Depending on how strong the human player or the other four AI-engined nobles are, the Pope will decide whether or not to endorse the claim. Therefore, attacking someone that claims the title can prevent them from getting it. Using diplomacy also allows the player to maintain high relationships with the other nobles and with the Pope, a useful feature to protect from attack. Alternately, the player can conquer everyone and even the Pope to win by default (in which case the anti-Pope will also endorse the player's claim to the throne).