She faced it all with her crisp and often sardonic British humor. After her first surgery and chemotherapy in 1993 caused her to shed 30 pounds from her size 14 frame, she joked that it was the first time in her life she looked remotely like the models featured on the pages of her magazine. After a 1995 bone-marrow transplant, when the chemotherapy turned a mole on her breast coal black, she quipped that it was “very Cindy Crawford,” but she also knew that it was an indication that she was “being fried from the inside out.” When she broke her wrist last January, she insisted on attending the Paris couture shows against her doctors’ advice, saying she would simply take notes with her other hand. “She did so much under extraordinary circumstances,” says Grace Coddington, her closest friend and the fashion director at rival Vogue. “I saw her depressed twice the entire time, and I include the last week. She never let go.”

Tilberis and Coddington met at British Vogue in 1969, when Tilberis–then Liz Kelly, daughter of a doctor from Bath–started her career as a summer intern. “I never had the slightest idea about or interest in the editing of a fashion magazine,” she wrote in her autobiography. “All I cared about was being able to hand Jean Shrimpton a pair of shoes.” After graduating from design school and marrying her college tutor Andrew Tilberis, she returned to Vogue as an assistant and worked her way up to editor in chief, an almost unheard-of ascension. It was there, working on fashion shoots, that she honed the love of photography–and photographers–that she later transferred to Harper’s Bazaar. Just a year after her arrival at Bazaar in 1992, she won National Magazine Awards (the industry’s highest honor) for photography and for design. “One thing I think she would like to be remembered for is that she really made photographers tick,” says Bruce Weber, who worked with her on countless British Vogue sittings. “She knew that by giving them something that would make their hearts beat a little faster that she’d get a better picture. She was so smart that way.” She indulged Weber’s passion for populating photographs with “real” people. “She was the first one who really let me photograph girls without hair and makeup, and she loved good-looking guys in the pictures.” In Los Angeles, when the good-looking guy was a little-known actor named Matt Dillon, he complained that he was a prop for the models rather than the focus of a shoot. “Pinch a bottom from time to time,” Tilberis told him, “and you’ll feel better.”

At the helm of British Vogue, she made her mark by befriending Princess Diana, who let Tilberis run groundbreaking sexy photographs of her by fashion photographer Patrick Demarchelier. When Tilberis went to Bazaar, Diana presented her with a special award from the Council of Fashion Designers of America in 1994. She had also agreed to write the foreword to Tilberis’s book, but she was killed the day after an aide relayed that message to Tilberis.

Tilberis and her husband adopted two boys–Robert, now 17, and Christopher, 14–after failing to conceive children of their own. (Tilberis was convinced that her nine fertility-drug treatments were linked to her cancer.) She was a devoted mother; being home in the evening with her sons was a priority, Coddington says. Bruce Weber recalls a shoot years ago in Nebraska, just before she adopted her first son. During a break at a public swimming pool, the pair decided to photograph all the little boys swimming there. “She dressed them all in long white shirts, and she was great with them,” Weber recalls. “I think that trip is when she realized she’d be a good mother. That’s what she always was to us.”