Britain’s National Gallery said Tuesday it will use 375 million pounds ($510 million) in donations to construct a new wing that for the first time will allow the institution to display modern art created after 1900.

The funds include two public gifts of 150 million pounds each from the Crankstart foundation, set up by Silicon Valley venture capitalist Michael Moritz and his wife, writer Harriet Heyman, and the Julia Rausing Trust, run by Tetra Pak heir Hans Rausing. The gallery said the donations are among the largest ever publicly reported by any museum or gallery.

Founded in 1824, the National Gallery’s collection is known for Western paintings spanning medieval times through the 19th century by artists such as Leonardo da Vinci, J.M.W. Turner and Vincent van Gogh. The gallery has traditionally held almost no works created after 1900, leaving modern and contemporary holdings largely to institutions such as Tate Modern. The planned wing will be built on land adjacent to the gallery’s Trafalgar Square site that is currently occupied by a hotel and offices.

An architectural competition will be held to select a design for the new building, the gallery said. It also said it will develop its post-1900 collection in collaboration with Tate, which holds the U.K.’s leading collections of British art and international art from the 20th century onwards.

National Gallery director Gabriele Finaldi described the project as an expansion of the museum’s mission. "The aim is to be the place where the U.K. public and visitors from across the globe can enjoy the finest painting collection in the world from medieval times to our own, in a superb architectural setting," he said.

Tate director Maria Balshaw welcomed the planned partnership, saying Tate "looks forward to working closely with colleagues at the National Gallery on loans, curatorial and conservational expertise to support the development of their new displays." The institutions did not disclose detailed plans for specific works or timelines for acquisitions and displays.

The gallery said the funding will support both the construction of the new wing and an expanded collection of works created after 1900. It did not give a timetable for the architectural competition or for the new wing’s completion. Officials said future announcements will outline next steps, including curatorial plans and the scope of joint work with Tate.

Museum leaders and donors have in recent years pursued major capital projects to broaden access and update facilities, and the National Gallery’s move marks a notable shift in Britain’s museum landscape by bringing modern painting into one of the nation’s most visited historic institutions.

The gallery’s announcement follows a period in which London’s cultural institutions have both competed and cooperated over loans, exhibitions and new spaces. The National Gallery’s addition of modern works is likely to prompt further coordination among national museums over collecting priorities and visitor programming, though specific arrangements will be worked out in consultation between the institutions and their trustees.

The National Gallery said the gift package included the two largest donations it has publicly disclosed and thanked the donors for enabling what it characterized as a once-in-a-generation expansion. Further financial details and a formal plan for the architectural competition were not provided in the announcement.