Kate Middleton is known for the rare combination of simplicity and elegance in her choice of dresses. This time, however, she turned up looking decidedly different.

The Duchess of Cambridge wore a dazzling Jane Corbett hat, while attending the Trooping the Colour ceremony held to honour the Queen's birthday. The hat was teamed with a silver-grey Erdem dress and Kate travelled with the Duchess of Cornwall (who wore a pastel blue jacket and pearl choker) in a horse-drawn carriage. Jane Corbett seems a favoured designer for Kate Middleton, given she wore a pink coloured hat for a garden party during the Queen's diamond jubilee celebrations.

Meanwhile, the Trooping of the Colour ceremony marks the official (real) birthday of the British monarch. It is an interesting tradition that sees every king/queen have two birthdays - one private (generally on the actual date of birth) and one public (held early in June, when there is the promise of good weather and meant to involve the whole country). The Queen's real birthday is 21 April.

Also present at the parade was her husband, Prince Philip, the Duke of Edinburgh, who has recently been released from the hospital after suffering from a bladder infection.

The Queen wore a buttercup Angela Kelly outfit she earlier wore for the royal wedding (that of Prince William, the Duke of Cambridge and Kate Middleton) in 2011 and the hat she chose was worn during her trip to Australia, earlier in the year. The Queen and her husband inspected a long line of troops wearing traditional red tunics and bearskins and were later due to travel in an open-topped ivory-mounted phaeton carriage. Those plans, however, were changed after bad weather played spoilsport.

According to the Daily Mail, some 1,600 officers and soldiers in traditional uniforms of the Household Cavalry, the Royal Horse Artillery and the Foot Guards took part in the parade, with more than 200 horses and around 290 musicians from 10 bands and corps of drums. After the ceremony, the King's Troop Royal Horse Artillery fired a gun salute in Green Park to mark the Queen's official birthday, while the Honourable Artillery Company fired a 62 round salute from the Tower of London.

Prime Minister David Cameron and his wife Samantha, the Defence Secretary Philip Hammond and General Sir David Richards, the Chief of the Defence Staff and the Prince of Wales, who is Colonel of the Welsh Guards were present. Also present were the Princess Royal, the Colonel of the Blues and Royals, and the Duke of Kent, Colonel of the Scots Guards, Duke of York with his daughters, Beatrice and Eugenie, the Earl and Countess of Wessex and King Abdullah II of Jordan.

Members of Britain's Royal family watch a flypast by the Red Arrows as they stand on the balcony of Buckingham Palace following the Trooping the Colour ceremony in central LondonReuters
Members of Britain's Royal family stand on the balcony of Buckingham Palace following the Trooping the Colour ceremony in central LondonReuters
Britain's Camilla, Duchess of Cornwall, and Catherine, Duchess of Cambridge travel to Horse Guards Parade for the Trooping the Colour ceremony in central LondonReuters
Britain's Catherine, Duchess of Cambridge travels to Horse Guards Parade for the Trooping the Colour ceremony in central LondonReuters
Britain's Queen Elizabeth inspects guardsmen during the Trooping the Colour ceremony on Horse Guards Parade in central LondonReuters
The UK has a statutory minimum of 28 vacation days but just eight public holidays for a total of 36 days.Reuters