During her lifetime, Isabella Stewart Gardner amassed a significant art collection, including works by Titian, Rembrandt, Michelangelo, Raphael, Botticelli, Manet, Degas, Whistler, and Sargent. She also collected furniture, rare books, textiles, and decorative objects. By 1896, Isabella and her husband, Jack Gardner, contemplated how they could find additional space for their growing collection. They considered expanding their home (152 Beacon Street) but eventually began to discuss an entirely separate property. In 1897, the couple began planning for their eventual building project by traveling to Italy and drawing inspiration from Venetian palazzos; however, Jack died suddenly in 1898. In 1899, Isabella purchased a plot of land in Boston’s Back Bay Fens region, and work began under the supervision of architect Willard Sears.

Construction on the mansion (initially known as Fenway Court) took place between 1899 and 1901, with Isabella playing an active role in supervising the building and visiting the site every day. Isabella moved into apartments located on the building’s fourth floor in 1901 and began installing her art collection in 1902. For the remainder of her life, she actively arranged and rearranged the art at Fenway Court. The design of the building draws on a range of influences from different regions and historical periods; it is notable for the focus on a central interior courtyard garden.