Britain’s Iron Lady was laid to rest Wednesday following a service that paid tribute to a life marked with political controversy and a small but vocal protest along the procession route.

More than 2,000 mourners attended the funeral of former prime minister Margaret Thatcher at St. Paul’s Cathedral. Among them were dignitaries representing more than 170 countries, including a Canadian contingent of Prime Minister Stephen Harper, Foreign Affairs Minister John Baird, former prime minister Brian Mulroney and Gordon Campbell, Canada’s high commissioner to the United Kingdom.

Queen Elizabeth II and her husband Prince Philip were also in attendance, as were former British prime ministers John Major, Tony Blair and Gordon Brown. There were several celebrities on hand, including singer Shirley Bassey and composer Andrew Lloyd Webber.

Thatcher’s coffin, draped in the Union Jack and topped with flowers and notes from her children, was carried atop a horse-drawn carriage through the streets of central London prior to the service. Thousands of spectators lined the streets to catch a glimpse of the procession – some applauded and others booed as it passed by.

“Margaret Thatcher was a very divisive figure,” CTV’s Tom Kennedy said from London. “Even her former allies have said she was a divisive figure in life and she continues to be so in death.”

Thatcher died on April 8 at age 87 following a stroke.

Nicknamed the Iron Lady for her steadfast belief in the free market and her strong opposition to unions, Thatcher transformed Britain during her 11-year tenure from 1979 to 1990, privatizing state industries and deregulating the economy.

“There will be great division over whether she was good for Britain in the long run, or bad for Britain,” Kennedy said. “But I think internationally she was a very, very important figure. And domestically, whether you liked her or not, she had a tremendous impact on this country.”

Some staged silent protests by turning their backs upon the coffin as it passed, while one man held a banner declaring "Rest in shame."

Along the route, arguments broke out in the crowd between Thatcher supporters and opponents.

Taking note of the protesters, Mulroney said Wednesday that when leaders tackle the “structural challenges” facing society, at least half of their constituents are going to disagree with their positions.

“She revolutionized the United Kingdom, and in the process, she irritated a lot of people and some of them are still here,” Mulroney told CTV News in London. “But the good works will live on in history.”

In his funeral sermon, the Bishop of London Richard Chartres said Thatcher is at peace after “a life led in the heat of political controversy.”

"The storm of conflicting opinions centres on the Mrs. Thatcher who became a symbolic figure -- even an ism,” he said. It must be very difficult for those members of her family and those closely associated with her to recognize the wife, the mother and the grandmother in the mythological figure."

"There is an important place for debating policies and legacy ... but here and today is neither the time nor the place," he added.

The funeral, which was largely planned by Thatcher years before her death, included a reading by the late prime minister’s granddaughter Amanda Thatcher, as well as from the current British Prime Minister David Cameron.

Music from British composers played as mourners filed into the church and readings included a passage from T.S. Eliot.

The younger Thatcher read a passage from Ephesians: “Stand therefore, having your loins girt about with truth, and having on the breastplate of righteousness.”

After the service, church bells rang as Thatcher’s coffin was carried out. As per her wishes, she will be cremated.

More than 700 soldiers, sailors and air force personnel lined the route to the cathedral and around 4,000 police officers were on duty.

CTV’s Ben O’Hara-Byrne said that in the wake of the Boston Marathon bombings, “there was no doubt extra precaution taken” with security. However, despite the heavy police presence, “as you walked along the procession route you got the impression they were trying to be as unobtrusive as possible.”

The ceremonial funeral with military honours is reported to have cost taxpayers $15 million.

Some guests who sent their regrets were U.S. first lady Nancy Reagan -- whose husband Ronald had a close relationship with Thatcher -- and former Soviet leader Mikhail Gorbachev, who shared key moments in history with the late prime minister. Former U.S. presidents Bill Clinton and George Bush declined to attend the funeral.

Alicia Castro, Argentina's ambassador to the U.K., also declined. Thatcher went to war in 1982 to retake the Falkland Islands after Argentina invaded the remote British territory off the South American coast.

With files from The Associated Press