Poher is an ancient principality that emerged in the
Early Middle Ages in
Cornouaille in west-central
Brittany. Its capital was the Gallo-Roman city of Vorgium, capital of the
Osismii, which became
Carhaix after the
fall of the Roman Empire. Archaeological excavations scheduled since 1999 show that, even if the city lost its function as capital after the 4th century, it was nonetheless a stronghold and major strategic crossroads.