The castle was built between 1279 and 1282 by order of Charles I of Anjou, from whom it gets its original name, the Maschio Angioino (the Angevin Keep). It was called the "new" castle after extensive renovations commissioned by Alfonso of Aragon, following his victory over the French. Its original appearance is only visible in the Chapel of Santa Barbara, with frescoes (almost entirely vanished) by Giotto and his student, Maso di Banco. The reconstruction extended and fortified the structure. The marble entrance arch of the castle is of interest: numerous artists participated in creating this celebratory declaration of the Aragonese victory. Within the castle are housed the Neapolitan Society of National History (founded in 1875), possessing roughly 170 thousand volumes, drawings, prints, and manuscripts; and also the Civic Museum, which guards a rich collection of art works originally in Neapolitan churches.