The first nucleus of the Library and Art Collections promoted by Luca Beltrami, a figure of great importance both for the city of Milan and for the Castle, was already active at the beginning of the 1900s in what is now the Treasury Hall (Sala del Tesoro), together with other holdings. The bombings of 1943, which devastated other institutes within the Castle, such as the Civic Library, spared the Art Collections Library. Following the war, this initial nucleus continued expanding and taking form to become the Biblioteca d’Arte and in the early 1950s found a home in the Courtyard of Arms where it is housed to this day. Here it was further opened to the public and to a constant scientific enrichment. Its horizons extended to gradually encompass not only art and applied arts, but also museology, museum design, graphic design, design, fashion and the visual arts in general.