They came to pay their respects to the widow of a former U.S. president and to their old friend. There was former British prime minister Margaret Thatcher, former Soviet leader Mikhail Gorbachev, former Japanese prime minister Yasuhiro Nakasone and Canada's Brian Mulroney.
Minutes after paying his respects to Nancy Reagan on Thursday, Mr. Mulroney recalled how, from the first time he met her late husband more than 20 years ago, there was a special chemistry between him and Ronald Reagan.
"We were both Irish. We both enjoyed life. Our wives got along extremely well," Mr. Mulroney said, harking back to 1983 when as then-leader of the opposition Progressive Conservatives, he travelled to Washington to see the U.S. President.
"Usually, a leader of the opposition gets five minutes and a handshake from a president," the former prime minister said in an interview. "Our meeting went on for a very extended period of time and we had a joint press conference in the Rose Garden."
It was the start of not just a close political relationship, which led to the signing of the landmark Canada-U.S. free-trade agreement in 1988, but a personal one as well. Mr. Mulroney and his wife, Mila, became close family friends of the Reagans.
Today, Mr. Mulroney will join U.S. President George W. Bush, former president George Bush and Mrs. Thatcher in giving eulogies at Mr. Reagan's state funeral in Washington's National Cathedral.
Mr. Mulroney, 65, would not disclose the contents of his eulogy, promising only that he would not speak for long. "I'm going to paint a picture of a man whom I saw as one of the great presidents of the United States."
But there was an indication of the tenor of his feelings in the inscription he and his wife made on Wednesday in the condolence book in Blair House, the presidential guest house, where Mrs. Reagan received a long line of mourners on Thursday.
"For Ron, with affection, admiration and respect," the Mulroneys wrote. "The Gipper always came through."
Mr. Mulroney talked with Mrs. Reagan, 82, for more than half an hour. He was impressed by how well she was coping with the national mourning for her husband, who died on Saturday at the age of 93. "I thought that given the oppressive heat of the day and the exhausting day she had put in...she looked very good, overwhelmingly sad but very serene."
Mr. Gorbachev and Mrs. Thatcher were also among the many visitors. The former British leader signed the condolence book with "To Ronnie - 'Well done, thou good and faithful servant.'"
In the interview, Mr. Mulroney recalled that he and Mr. Reagan saw eye to eye on a range of issues. "We were both free traders and private-sector oriented," he said, adding that they agreed on global issues, particularly the Cold War.
Above all, Mr. Reagan appreciated the marked absence of anti-Americanism, which Mr. Mulroney said the Liberal Party at the time had developed "to a shriek."
"I was criticized by the left, those tender Canadian nationalists whose sensibilities were so affronted when two Irish guys sing along When Irish Eyes Are Smiling," he said, referring to the 1985 Mulroney-Reagan Shamrock Summit in Quebec City, which touched off the free-trade talks.
Still, Mr. Mulroney, now a Montreal lawyer and corporate director, said he had his disagreements with the Republican president and made his disagreements known.
"I said no to Reagan on SDI [the Strategic Defence Initiative missile plan] I said no on Nicaragua. I said no on Cuba and I said no on South Africa."
Mr. Reagan had "full and total respect for Canadian sovereignty" and had "a very generous view of Canadian sovereignty," he said. And Mr. Mulroney said that were it not for Mr. Reagan's personal lobbying effort on behalf of free trade in Congress, the project would have died.
"Any time we had a bilateral problem, I'd call him at the White House, in Camp David or at Santa Barbara and he'd always be extremely responsive," Mr. Mulroney said.
He said he last saw Mr. Reagan about 10 years ago, shortly after the former president publicly announced that he was suffering from Alzheimer's disease. Mr. Mulroney, who lost his mother to the same ailment two years ago, believes it was a courageous thing to do.
"He did a marvellous thing by bringing it to public attention. He did a tremendous amount of good for Canadians and people around the world."