Queen Elizabeth II marked her ceremonial birthday overnight with the traditional "Trooping the Colour" parade in the heart of London — and 23-month-old Prince George made his debut on the Buckingham Palace balcony. The queen was joined by senior royals including the Duchess of Cambridge, who made her first appearance in public since leaving the hospital with newborn Princess Charlotte six weeks ago. There was no sign of Charlotte but George captivated throngs of well-wishers by appearing on the balcony in the arms of his father, Prince William, who was in full military garb. It was the first time George took part in the royal tradition of gathering the extended family on the balcony on important national occasions. He was the youngest person there; great-grandfather Prince Philip, 94, was the oldest. Prince Charles, William and Princess Anne were on horseback for the start of the annual ceremony, later joining the others on the balcony. The queen turned 89 on April 21, her actual birth date, which is traditionally marked in private, with a public celebration held in June, when London's fickle weather is more likely to be favourable. Crowds gathered outside Buckingham Palace to view the festivities though the day was cloudy and cool. Elizabeth, wearing a peach and silver coat dress with a matching hat, inspected 1,100 soldiers from the Household Division at the Horse Guards Parade grounds near the palace. She arrived in an open-topped Ascot Landau carriage. The Duchess of Cambridge, formerly Kate Middleton, wore a blue and white dress by Catherine Walker and a whimsical white hat by Lock and Co. for the occasion. She arrived with Camilla, the wife of Prince Charles. Kate and William and their two young children have spent much of the time since Charlotte's birth at their country retreat on the queen's estate at Sandringham in rural Norfolk. William has resumed his job as an air ambulance pilot after taking a break for paternity leave.