LONDON — The Duchess of Cambridge gave birth to a boy on Monday, Kensington Palace announced. It is her third child with Britain's Prince William, who accompanied his wife to the hospital. The baby weighed 8 pounds, 7 ounces. His name was not immediately announced. The duchess, who was formerly known as Kate Middleton, had been admitted to the Lindo Wing of St. Mary’s Hospital in London earlier Monday. She gave birth at 11:01 a.m. local time (6:01 a.m. ET), royal officials said. Kate and Prince William left the hospital with the infant prince barely eight hours after he was...