Duchy of Brittany

The Duchy of Brittany was a medieval state located in the northwestern region of France, with its capital at Nantes. It was established in the 9th century as a separate entity from the Kingdom of France and had its own ruling dynasty. The Duchy maintained a certain degree of autonomy, but was often contested by the French monarchy and other neighboring states. It was united with the French crown in 1532 through a marriage alliance, but retained its own legal and administrative systems.

Ingame Description
Brittany, the old lands of the Britons. With their mountains, and with a Celtic spirit, have now separated themselves from the French. Will the celts return the land they populated before Rome, or fall to invaders once more?

Trivia

 * Brittany can also separate if there is a rise of pan-Celticism across Scotland, Wales, Cornwall, and Ireland.