SEVENTY YEARS AGO, U.S. NAVY Lt. Richard Byrd claimed to have flown over the North Pole. So did Italian Army Col. Umberto Nobile. But Byrd's airplane flight, on May 9, 1926, appeared to be a historical first and made him an international hero; No-bile's accomplishment, three days later, made him a historical footnote and his ship, the dirigible Norge, an enormous gas-filled runnerup.

Until now. Last month, Dennis Rawlins, a navigation expert, released a study of Byrd's diary, recently discovered at Ohio State University, in which a number of entries and an incriminating erasure provide fresh evidence of what many skeptics had long suspected: that Byrd turned around 150 miles short of the Pole. Ohio State plans to publish the diary.

If the findings hold up, history books will have to be rewritten to give credit to Nobile and his co-adventurers, Norwegian explorer Roald Amundsen—who had reached the South Pole, on foot, 14 years earlier—and American coal-mining heir Lincoln Ellsworth. Although Nobile wasn't as lionized as Byrd, he did receive honors, including an invitation to the White House. (Titina, the terrier who accompanied him everywhere, relieved herself on a carpet, to Calvin Coolidge's amusement and Nobile's mortification.)

Resentful of Nobile's popularity, Amundsen claimed the Italian had merely been the dirigible's "hired pilot"—a charge that still moves Nobile's widow, Dr. Gertrude Nobile, 79, a retired librarian, to laughter. "[Nobile] built the ship. He prepared the route. He was in command," she says. Despite the quarrel, when Nobile's airship Italia went down over the Pole during an exploration two years later, Amundsen joined the search—and disappeared with his plane.

Nobile, rescued four weeks later but only after eight of his crew had perished, died at 93 in 1978. (Titina, stuffed, is in an aeronautics museum near Rome.) "His last years were peaceful, but the tragedy of the Italia always remained on his soul," says his widow. Would he have been pleased to be known as the first over the Pole? "Oh, yes, I think so," she says with quiet pride.