The Welsh translation of Caernarfon Castle is Castell Caernarfon. The first mention of there being a castle in Caernarfon is around 1088, it was built on the orders of Hugh d’Avranches, Earl of Chester, otherwise known as Hugh the Fat, or Hugh the Wolf.
In 1282 and 1283, Edward I of England began to establish English rule over Gwynedd and the rest of North Wales. For defence against the native Welsh, Edward built castles across the northern coast of Wales and the English-Welsh border. The key castles were: Beaumaris, Conwy, Harlech, and Caernarfon. The man behind the construction of these castles was James of Saint George, a Savoy-born architect and a military engineer, who was oversaw by Edward’s queen, Eleanor of Castile. The ‘Flores Historiarum’ writes that the body of a fourth century Roman emperor, Magnus Maximus, was found during construction and later buried in a local church, possibly the one just opposite the castle. It can be seen from Caernarfon’s towers. By the end of construction, the Caernarfon was garrisoned with between twenty and forty men, other castles would be guarded with much less
Edward II of England was born at Caernarfon in 1284. Traditionally, it is thought he was born in the Eagle Tower, a tower inspired by the Crusader castles and those of Eleanor of Castile’s homeland. It is, however, unlikely, that Edward was born in Eagle Tower. Construction on the castle had only began the year before, so by the time of Edward’s birth, the tower would consist only of the starting foundations. Madog ap Llywelyn led a rebellion against the English in 1294 and attacked Caernarfon. He took the castle, which was defended by only a ditch and a simple barricade, before setting alight anything he could. A year after the English retook the castle and began to add more fortifications to the town and castle.
Accommodation suites were built in Caernarfon, as they were in all the Welsh castles, but none of these were visited until 1399, when Richard II of England, a prisoner of his cousin, the future Henry IV, passed through them to make stops at Conwy Castle and Flint Castle . Welshmen known to have stayed at the castle, include: Llywelyn the Great and Llywelyn ap Gruffudd.
Caernarfon would not be attacked again until the 15th century by Owain Glyndwr in his Welsh Uprising against Henry IV of England. The uprising was mainly fuelled by the rivalry and the political tensions between him and Reginald Grey, the Baron Grey de Ruthyn. Owain besieged Caernarfon with French aid, but he was unsuccessful in his attenpts. Though his capture of the castle had come very close.
The Welsh Castles of Edward I by Arnold Taylor (The Hambledon Press, London, 1986)