Le Ballet de l'Acier

A Duke who is advanced in noble title becomes a Peer. A Peer must have at least one chateau in order to advance.

A Prince does not advance in title but may advance in Social Rank. A Prince of Social Rank 15 who advances is recognized as a Foreign Prince. A Foreign Prince must have at least two chateaus in order to advance.

The titles of Archduke and Grand Duke are no longer used.