Like every good royal wedding, it was all about the hats, the dresses and the posh tails in Windsor. Early guests included Oprah Winfrey, who sauntered into St. George's Chapel in Stella McCartney pink for the wedding Saturday of the Prince Harry and Meghan Markle.

Winfrey's wide-brim hat was a well-plumed accessory to her soft tiered day dress. Idris Elba, meanwhile, beamed in a dark blue suit while Princess Diana's brother, Earl Spencer, opted for a morning coat.

Amal Clooney came in a mustard yellow Stella McCartney dress with cap sleeves and a long tie in back that bordered on a train as she glided into St. George's Chapel. Her actor husband, George Clooney, was at her side in neutral grey and a pale yellow stripe tie.

Others seen arriving Saturday were Serena Williams and David and Victoria Beckham, who walked in the bright sunshine onto the grounds of Windsor Castle. They were among 600 celebrities, royalty, athletes and family friends invited to St. George's Chapel for the wedding.

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The wedding was a global event, thanks to Harry's status as a senior British royal and Markle's celebrity after starring on the U.S. television series "Suits" for seven years. The wedding pomp and ceremony -- complete with Anglican prayers and tradition, classical music, a gospel choir and a horse-drawn carriage ride through Windsor -- was beamed live to tens of millions of TV viewers across the world.

As the day got underway, Queen Elizabeth II honored her red-headed, 33-year-old grandson with a new title: the Duke of Sussex, which means Markle is now the Duchess of Sussex. The queen wore a lime silk tweed coat and Angela Kelly hat with handmade lace crystals and pearls by Lucy Price.

Kate, the duchess of Cambridge, wore a primrose yellow wool silk tailored coat by the house of Alexander McQueen and large hat with a flower tucked under the brim on one side. She sat beside the groom's step-mother, Camilla, duchess of Cornwall, who also went large with a flat, feathery effect for a hat.

The mother of the bride, Doria Ragland, watched the nuptials in an understated hat and light green suit.

Markle was first seen in her wedding dress as she left her hotel Saturday on her way to the wedding, on a 10-mile trip to St. George's Chapel in Windsor. She waved for the cameras as the car she was traveling in -- a vintage Rolls-Royce -- drove past.

The archbishop of Canterbury later declared Prince Harry and Meghan Markle husband and wife at the chapel. Justin Welby, the head of the Church of England, made the proclamation after the couple promised to love and cherish one another "till death us do part," and exchanged rings. The British-American pair are now officially known as the Duke and Duchess of Sussex, and the duchess will take her place among senior members of the royal family.

Relatives at the ceremony included Charles Spencer, the brother of Harry's late mother Princess Diana, and Harry's cousin Zara Tindall and her husband. Also in attendance was the family of Prince William's wife Kate: Parents Carole and Michael Middleton, sister Pippa Middleton and brother James Middleton.

Pippa Middleton arrives in St George's Chapel at Windsor Castle for the wedding of Prince Harry and Meghan Markle in Windsor, Britain, May 19, 2018. POOL/REUTERS

Prince Harry's ex-girlfriend Chelsy Davy was also among the congregation, as was Sarah Ferguson, the Duchess of York, the ex-wife of Harry's uncle Prince Andrew.

The royal couple decided not to make a political affair of their nuptials -- even British Prime Minister Theresa May, the leader of the British government, was not in attendance. No political heads of state got an official wedding invite.

Outside the castle, thousands of fans crammed the streets of Windsor. Irene Bowdry, a lawyer from California, was aboard the jammed early train to Windsor. She booked her trip to England as soon as the wedding date was announced.

"An American in the royal family, isn't that so exciting?" she said.

The weather was balmy and clear, bathing the ancient stones of Windsor Castle in a beautiful spring light. Royal fans camped outside the castle for days, and British police stepped up security, with sniffer dogs, barricades and patrols all over town.

"Windsor is absolutely bursting with excitement," said royal historian Hugo Vickers. "There are cardboard cutouts of Meghan and Harry in every shop window, virtually. There's bunting all over the place. I've never seen so many people in the streets of Windsor."