Outside a foundry in Beacon, N.Y., last week, Peter Dent fought back tears at the sight of his late uncle's promise fulfilled: a 24-foot-tall, 15-ton bronze stallion. Charles Dent, who died at age 77 in 1994, had vowed to carry out Leonardo da Vinci's dream of creating the world's largest equine statue. "I felt my uncle's spirit," says Dent, 40.

Leonardo's spirit, too, must be riding high—thanks to Dent and sculptor Nina Akamu. The Italian Renaissance legend spent 17 years planning the colossus. But in 1499 the French invaded Milan and destroyed his 24-foot clay model with a hail of arrows. Leonardo fled, mourning his lost horse.

In 1977, Dent, a Fogelsville, Pa., retired airline pilot and amateur sculptor, read in National Geographic about the "horse that never was" and decided to bring it to life. "He dreamed big dreams," says his nephew. Dent gleaned information about the planned sculpture from Leonardo's notebooks, studied the artist's other drawings of horses and started a fund-raising effort that has raised $6 million in donations for the project.

After some false starts and Dent's death from Lou Gehrig's disease, volunteers enlisted Akamu, a Cold Spring, N.Y., sculptor. (She has also been chosen to create the centerpiece for the National Japanese American Memorial in Washington, D.C.) With six assistants, Akamu built a clay model from which 60 bronze panels were cast and welded over a stainless-steel skeleton. The horse is the world's largest in bronze. "A muscle is this long," marvels Akamu, stretching her arms wide.

This summer the horse heads to a permanent home near Milan's historic racetrack as a gift Peter Dent likens to the Statue of Liberty. (A second casting will stand in a park in Grand Rapids.) Leonardo's name is etched on its right eye, Charles Dent's on its left. Says Akamu, who signed its mane: "It symbolizes, over 500 years, two men's separate visions unified in a single vision."