The National Gallery of Art rapidly expanded its collection this week, in a boon of an agreement with one of the greatest private modern art collectors in the world, the Washington Post reports.

Philanthropist Robert E. Meyerhoff houses 265 pieces of phenomenal postwar artwork at his estate just north of Baltimore, and established a relationship with the NGA years ago, where you'll already find works by Picasso and Andy Warhol the family has loaned or donated. Meyerhoff, with his now deceased wife, Jane, had promised to donate the rest of their collection to the museum one day, but instead of shipping all the pieces to Washington, D.C., the two parties worked out an arrangement that will turn Meyerhoff's estate -- which sits on 250 acres and includes a horse breeding farm -- into a satellite wing of the NGA upon his death; Meyerhoff is 84.

They needed approval from the Baltimore County Council, who voted Monday in favor of the plan, with a few parking and opening hour restrictions, since it's not commercial land. The partnership is a new kind of off-site arrangement: The NGA won't own the estate, which will be run by an independent board with a budget from the Meyerhoff Modern Art Foundation, but they'll run programming and assist in maintaining the collection, and help turn it into "an exhibition center and study center for modern art."

Image of National Gallery of Art by Hoffmann