As Prince Charles and Princess Diana strive mightily to heal at least the appearance of a marital rift, they may be drawing on the example of another royal pair—one that has endured its own ups, downs, separations and rumors. This week Queen Elizabeth, 61, and Prince Philip, 66, quietly celebrate 40 years together, perhaps raising a glass to forebearance and patience. For them, what began as a love match has evolved into a comfortable sharing of children, affection and a love of horses.

When they wed in Westminster Abbey in 1947, she was "Lilibet," Britain's favorite princess and heir to its crown. He was her dashing third cousin and a Royal Navy lieutenant. Although Philippos Schleswig-Holstein-Sonderburg-Glücksburg had been born a prince of Greece, he'd become a British citizen by the time they married. Charles was born in 1948, and Princess Anne followed in 1950. But when Elizabeth became Queen in 1952, Philip found himself in the awkward role of consort with neither duties nor powers. He complained that he was little more than "an amoeba, a bloody amoeba," and the marriage predictably suffered. There were stories of other women, and in 1956 the prince set sail on a five-month voyage to Commonwealth countries. The usually reticent Buckingham Palace press office felt compelled to announce, "It is quite untrue that there is any rift." Indeed love and propriety—or, some would say, propriety and love—would not allow the marriage to fail. Philip returned, and the births of Prince Andrew in 1960 and Edward four years later testify to a damaged union dutifully repaired.

Today the royal couple sleep in separate bedrooms—as the world learned when an intruder broke into the Queen's boudoir five years ago—and spend much of their time pursuing separate interests and public duties. Nonetheless a longtime royal-watcher says Lilibet's feelings for her handsome older cousin have changed little. "She relies on him enormously," says the observer, "but apart from that, she simply adores him."