Cardiff Castle (Welsh: Castell Caerdydd) is a medieval castle and Victorian Gothic revival mansion located in the city centre of Cardiff, Wales. The original motte and bailey castle was built in the late 11th century by Norman invaders on top of a 3rd-century Roman fort. The castle was commissioned by either William the Conqueror or by Robert Fitzhamon, and formed the heart of the medieval town of Cardiff and the Marcher Lord territory of Glamorgan.