LONDON (CNN) -- With a special song, a brother's anguish, and pomp and circumstance befitting a princess, Britain bade a solemn farewell to its "queen of hearts" Saturday as millions watched worldwide.

Princess Diana's coffin was drawn on a gun carriage through central London to Westminster Abbey, where the royal and Spencer families gathered for the funeral service. Her remains were later buried on her family's estate in Northamptonshire.

Diana's brother Charles, the ninth Earl Spencer, took the opportunity in his eulogy to criticize what he characterized as the media's hounding of his sister.

"I don't think she ever understood why her genuinely good intentions were sneered at by the media, why there appeared to be a permanent quest on their behalf to bring her down. It is baffling," Spencer said, drawing applause both in the church and among crowds listening outside.

The capital's streets were densely lined with millions of mourners, who watched largely in silence as the cortege proceeded from Kensington Palace, Diana's London home, to Westminster Abbey. Some tossed flowers into the road, and many wept openly.

Three wreaths of flowers, from her brother and her sons, Prince William and Prince Harry, graced the flag-draped coffin. A card signed "Mummy" was nestled among the blossoms.

Members of the royal family stood together outside as the cortege passed Buckingham Palace. Britain's flag flew at half-staff at the official London royal residence for the first time in history.

As the cortege neared the palace, Prince Charles, Prince William, Prince Harry, the Earl Spencer and Queen Elizabeth's husband, Prince Philip, began to walk behind the coffin for the final mile. Representatives of Diana's favorite charities joined them.

The service was televised live worldwide, and people in London were able to watch on large screens set up in Hyde Park and Regent's Park. Members of the crowds, some clutching flowers and tissues, wiped away tears as they heard the hymns, readings and prayers for the "people's princess."

Buckingham Palace and the Spencers invited 2,000 people to the service, although official delegations were not included because it was not a state funeral.

Those attending included friends of Diana's through her philanthropic work and entertainers such as Sting, Luciano Pavarotti, and Elton John, who sang a rewritten version of his song "Candle In The Wind."

Dignitaries included U.S. first lady Hillary Rodham Clinton and former British Prime Minister Margaret Thatcher. Also in attendance were Mohamed Al Fayed and his wife, the parents of Dodi Fayed, Diana's companion killed with her in the car crash in Paris last weekend.

The service included readings by the princess's two sisters, Lady Sarah McCorquodale and Lady Jane Fellowes. British Prime Minister Tony Blair read 1 Corinthians 13, a New Testament passage about the qualities of love.

The hour-long program ended with a national moment of silence. The coffin was then taken in a hearse to the Spencer family estate in Northamptonshire for private interment. The roads were lined with still more mourners.

The queen and Prince Philip returned to Buckingham Palace, as Prince Charles and his sons attended the burial on an island on the Spencer estate grounds.

Much of normal British life came to a halt for the day. Supermarkets and museums were closed, and many sporting events were canceled.

"Today is our chance to say 'thank you' for the way you brightened our lives, even though God granted you but half a life," Spencer said in his eulogy, his eyes filling with tears.

"We will all feel cheated that you were taken from us so young, and yet we must learn to be grateful that you came along at all."