(LONDON) -- Britain said goodbye to Margaret Thatcher on Wednesday, the country's first female prime minister and its longest-serving prime minister of the 20th century.
The funeral for Thatcher, who died on April 8 at the age of 87 following a stroke, began Wednesday morning as her coffin, draped in a union flag, was transferred from the Palace of Westminster to St. Paul’s Cathedral.
There, more than 2,300 guests, including Queen Elizabeth II and her husband, Prince Philip, attended the service for the woman who was known as Britain's Iron Lady.
In all, dignitaries from about 170 countries were in attendance. Leading the U.S. delegation was James Baker, George Schultz, Henry Kissinger and Dick Cheney.
Following the service at St. Paul’s Cathedral, Thatcher's coffin was transported to the Royal Hospital Chelsea.
Later on Wednesday, two receptions are scheduled to be held.
"The Foreign Secretary will host a reception at the Mansion House for representatives from foreign states and other distinguished foreign VIPs. At Guildhall there will be a reception for friends and family of Lady Thatcher and representatives of UK institutions. The Thatcher family, the Prime Minister and other senior Ministers will attend both receptions," according to a statement from British Prime Minister David Cameron's office.
There will also be a private cremation at Mortlake Crematorium.
Thatcher's funeral, which was held with military honors, was guarded heavily in the wake of Monday's bombings at the Boston Marathon that left three people dead and more than 170 injured.
More than 4,000 police officers were on duty during the funeral Wednesday, fanning out across the city in an operation costing more than $5 million.
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