The real-estate mogul and his model bride celebrate in lavish fashion at Mar-a-Lago

Real-estate mogul Donald Trump tied the knot with his girlfriend, model Melania Knauss, in a lavish celebration Saturday.

The 58-year-old Apprentice star and his 34-year-old bride exchanged vows in an elegant, traditional ceremony that included Trump s daughter, Ivanka, reading from the scriptures.

The happy couple and their guests, including Today show hosts Katie Couric and Matt Lauer, former New York City mayor Rudy Giuliani, and television personalities Star Jones, Barbara Walters, Regis Philbin and Kelly Ripa, then celebrated with an extravagant reception inside a 17,000-sq.-ft. ballroom built at Mar-a-Lago, Trump’s Palm Beach, Fla. resort. Guests dined on steamed shrimp salad, beef tenderloin, caviar, lobster rolls, Grand Marnier chocolate truffle cake and Cristal champagne.

At the end of the meal, singer Billy Joel serenaded the crowd with “Just the Way You Are” – and made up lyrics about Trump to the tune of, “The Lady is a Tramp.”

Asked what he thought of the lavish wedding, American Idol judge Simon Cowell, told PEOPLE at the reception: “I give it a nine.”

For the ceremony Knauss wore a gown designed by the House of Christian Dior’s John Galliano, which was featured in Vogue magazine before the couple wed. The white duchesse dress required nearly 300 feet of material and featured a 13-foot train and a 16-foot veil. It took 1,000 hours to make and 550 hours to hand-stitch more than 1,500 crystal rhinestones and pearls in a swirl pattern.

Just days before the wedding, Trump – who has been married twice before – told PEOPLE he had no prenuptial jitters. “If I didn’t have a great woman, I would be much more nervous,” he said.

Trump, who remains friendly with his ex-wives, Ivana Trump and Marla Maples, predicted a long, happy marriage with Knauss. “I think it will be very successful,” he said.

As for the newlyweds’s future, Trump, who has four children, said more mini-Trumps could be in the works. “Melania would like to have children,” he said. “I’m up for it.”

For full Trump wedding photo coverage, see the upcoming issue of PEOPLE Magazine.