Much of the northern part of the inner bailey was built by John of Gaunt, a son of King Edward III, between 1372 and 1380.[1] This part of the castle is considered by historian Anthony Emery to be "the finest surviving example of a semi-royal palace of the later middle ages, significant for its scale, form and quality of workmanship".[1] Gaunt's architectural style emphasised rectangular design, the separation of ground floor service areas from the upper stories and a contrast of austere exteriors with lavish interiors, especially on the 1st floor of the inner bailey buildings.[14] The result is considered "an early example of the perpendicular style".[15]