The master mason responsible for the design and orchestrating the construction of the castle was probably James of Saint George, an experienced architect and military engineer who played an important role in building the Edwardian castles in Wales.
Stenhuggeren, der var ansvarlig for designet og udførslen af byggeriet på Caernarfon Castle, var sandsynligvis James of Saint George, der var en erfaren arkitekt og militæringeniør og spillede en vigtig rolle i opførelsen af Edvards borge i Wales.