Art collector Baroness Marion Lambert died on May 28, four days after being struck by a bus in London. She was 73.

“Art is the expression of ideas—some of them very foresighted—of lofty ideals, of political insights, and of deep-felt emotions,” she once told an interviewer, according to the Evening Standard, which broke the news.

In a statement to artnet News, Christie’s chairman and head of post-war and contemporary art Francis Outred describes Lambert as “intense, visionary, and powerful.” He continued: “She knew what she wanted in all aspects of life. Formidable and kind in equal measure, she will remain in our collective memory as one of the great collectors and a friend who will be deeply missed.”

In 2004, Lambert offered approximately 300 photographs at Phillips, de Pury & Company in a New York auction. The historic sale, which totaled well over $9 million, set new records for artists including Cindy Sherman, Mike Kelley, and Louise Lawler.

She was widowed in 2011 by Swiss banking magnate and fellow art collector Philippe Lambert. She reportedly maintained two households in Switzerland and Italy. The Evening Standard reports that Lambert may have been in the United Kingdom on a visit to her son, Henri.

“She was a wonderful woman,” a friend told the Standard, “very passionate about art and photography and her death has come as a tragic shock to us all.”

Rudolf Stingel, Untitled, 2007. Courtesy of Christie’s.

Lambert’s most recent art world venture involved a 2015 Christie’s auction of 306 objects. The sale, “A Visual Odyssey,” which culled pieces from her family’s holdings, was organized with the help of longtime friend and auctioneer (and artnet News contributor) Simon de Pury. The sale included works by Mark Bradford, Marilyn Minter, and Christopher Wool, among others.

As she told Adam Lindemann for his book, Collecting Contemporary: “People who only buy art to invest, sooner or later will fall flat on their faces.”