With the Trumps, Obamas, Clintons and Carters sharing a pew, this is one of the rare occasions so many presidential figures can be seen all together.

The hearse carrying the remains of former President George HW Bush has arrived at the National Cathedral, after one last drive-by his old home.

Image source, Reuters

Former Canadian prime minister Brian Mulroney is to deliver one of the eulogies at the funeral for George HW Bush.

Mr Mulroney served as Canada's prime minister between 1984-93, with his second tenure overlapping that of the former president.

But the two leaders had gotten to know each other during the time former president Bush served as Ronald Reagan’s vice-president.

They have been recognised as having a historic, close working relationship.

Mr Mulroney once told Dorothy "Doro" Bush Koch for her memoir My Father My President that: “From the very beginning of our relationship, I found him to be a very interested and interesting personality.”, external

As prime minister, Mr Mulroney sought closer ties with the United States, including on major trade issues.

The two helped lay the groundwork for the Canada-US Free Trade Agreement, agreed on by both countries in 1987.

That agreement helped to cement the trading relationship between the two nations.

It was superseded by the North American Free Trade Agreement, or Nafta, in 1994, which eliminated many of the trade barriers and tariffs in place between North American nations, including Mexico.

Mr Mulroney and the former president also signed a key environmental accord in 1991, credited with reducing acid rain during the 1990s., external

He was trusted enough by George HW Bush to convey private messages from the president to Soviet leader Mikhail Gorbachev as the Berlin Wall fell.

The pair said that relationship, and their mutual respect, allowed them to tackle tough issues that arose during various negotiations between both countries.

Mr Mulroney met as recently as September with the former president when he received the George Bush Award for Excellence in Public Service.

The Trumps have arrived and, as predicted, we've just witnessed a really uncomfortable handshake between the current president and former President Barack Obama and former First Lady Michelle Obama, as they took their seats.

A homily on forgiveness wouldn't go amiss...

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Former President Bill Clinton and former First Lady and Secretary of State Hillary Clinton have also arrived.

The BBC's Anthony Zurcher reports that a choir has begun singing as Bush Sr's hearse approaches the cathedral.

The service is to begin at the top of the hour.

Eimear Flanagan
BBC News NI

Image source, The Irish Tenors

The Irishman who will sing at George HW Bush's funeral also visited him on his deathbed and sang to the former US president just hours before he died.

The New York Times reported that Ronan Tynan asked to visit Bush Sr and sang Silent Night for him. The former president passed away that same day.

Tynan has been performing for high-profile US politicians for many years.

Read more about the man once described as "America's favourite tenor" here.

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The Bush family has left the US Capitol.

A military guard carried the former president's casket down the Capitol steps and placed it inside the hearse.

They are making their way to the National Cathedral, an approximately 20-minute journey.

The route is lined by mourners paying their respects.

Former Secretary of State Condoleezza Rice has arrived at the National Cathedral.

Former Vice-President Joe Biden, former British Prime Minister John Major and his wife Jill, as well as and Maine Senator Susan Collins were also seen at the cathedral.

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As the funeral for former President George HW Bush begins, flags across the nation are flying at half-mast.

And they will be for the next 30 days, per a proclamation from President Donald Trump.

It's standard procedure for a presidential death based on guidelines, external set during the 1950's under President Dwight Eisenhower.

Those rules say the flag should fly at half-staff for 10 days after a vice-president, Supreme Court chief justice, or House of Representatives speaker's death.

For senators and representatives, the flag will be lowered on the day of death and the day after.

The death of a governor will see the flag at half-mast until interment.

Of course, the president ultimately has the authority for how long to order a flag to fly at half-staff.

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The extended Bush clan will attend Wednesday's funeral en masse, including Bush Sr's many grandchildren.

So who are they?

Laura Bush: The former first lady as wife of President George W Bush, she was one of the most popular First Ladies in US history.

Jeb Bush: You might remember this former Florida governor from the 2016 elections, where he dropped out after a disappointing Republican primary showing.

Columba Bush: Jeb Bush's wife, she is a Mexican-American philanthropist known for promoting the arts and women.

Neil Bush: One of Bush Sr and Barbara Bush's six children, he is a businessman.

Maria Bush: Neil Bush's second wife, Maria Andrews, was once friends with Bush's first wife Sharon, and the relationship was a controversial part of a messy divorce.

George P Bush: Bush Sr's grandson, he is currently serving as the Texas Land Commissioner and is tipped as a possible next-generation Republican star.

Jenna Bush Hager: One of George W Bush's two twin daughters, she is a journalist and NBC News correspondent.

Barbara Bush: Jenna's twin, Barbara - named after their former first lady grandmother - is a co-founder of the nonprofit Global Health Corps.

Lauren Bush Lauren: One of Bush Sr's three granddaughters, she is the daughter of Neil Bush. She is the co-founder of nonprofit FEED Projects and the wife of designer Ralph Lauren's son, David.

Read more about the Bush dynasty here.

On the row directly in front of the pulpit will sit President Donald Trump and his wife, Melania, along with former Presidents George W Bush, Jimmy Carter, Barack Obama, Bill Clinton and his wife - Trump's 2016 Democratic rival, Hillary Clinton. Trump's relations have been fraught with all of them. His rise to the head of the Republican party saw him ridicule Bush Snr's "thousand points of light" phrase, slam Bush Jr's 2003 invasion of Iraq as "one of the worst decisions in the history of our country", and derail Jeb Bush's White House campaign by tarring him with the epithet "low energy". But it was all smiles as the Trumps welcomed George and Laura Bush to presidential guest accommodation Blair House yesterday. Trump raised eyebrows by taking a presidential motorcade all of 750ft across Pennsylvania Avenue to welcome the Bushes.

Image source, EPA

Canada's parliament is flying the flag on the Peace Tower today in honour of the former US President.

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George HW Bush: political insider, war hero and diplomat.

Click through for a look at his most memorable moments.

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Among the political leaders and world dignitaries attending today's funeral's will be a handyman.

Mike Lovejoy is an electrician from Kennebunkport, Maine.

He was Bush Sr's dedicated Mr Fixit for years, doing everything from turning wrenches to going shopping with the 41st president for a new TV, he told WGME News, external.

Lovejoy said he was surprised and honoured to have received an invite to the private ceremony.

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It's not just the US that's mourning. Kosovo, a disputed country in the Balkans region of Europe, has declared a national day of mourning for George HW Bush Sr, a man seen as a powerful ally to its Albanian population.

Flags fly at half-mast in honour of the former president, and schools in Kosovo discussed the US commander-in-chief as the first order of business this morning.

But why?

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In 1992, Bush Sr wrote a letter to the president of Serbia threatening US military action if Serbia launched a war in Kosovo, which was then still a part of Serbia.

The US eventually helped push Serbia to leave the region, and Kosovo became independent in 2008.

In Pristina, the capital, there's even a street named after Bush Sr’s son, George W Bush, who also supported the new nation.

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Photos of Sully, Bush Sr’s service dog, resting beside his coffin have gone viral ahead of the president’s funeral.

He was present at the Rotunda on Capitol Hill yesterday, when lawmakers and top officials came to pay tribute to Bush Sr.

The two-year-old Labrador was trained to open doors and fetch items among other commands to help Bush Sr.

Sully will continue to serve, now as a therapy dog for wounded soldiers.

You can keep up with Sully via his Instagram, sullyhwbush, external.

Nick Bryant
BBC New York Correspondent

Image source, Howard L. Sachs/CNP/Getty Images

Americans have not just been mourning the passing of a president, but also the vanishing of a bygone politics.

For George Herbert Walker Bush was the last president of America's greatest generation: a war hero who bemoaned the end of the patriotic bipartisanship of the early post-war years; a moderate who was genuine when he vowed to make his country kinder and gentler; a pragmatist who viewed with suspicion the rise of ideological Republican purists who fetishised tax cuts and demonised government.

For many his death marks the end of an era, but the truth is that age of American politics drew to a close a quarter of a century ago.

Read the full analysis here.

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Bush has lain in state at the US Capitol since Monday, where many thousands of people have filed past his coffin to pay respects.

In case they didn’t know who they had come to mourn, a card proudly ticking off his pedigree was handed to each mourner. It read like a resume, listing Bush's federal jobs.

So who was he?

George Herbert Walker Bush Sr served as the 41st president between 1989-93, seeing America through the end of the Cold War.

He was a World War Two veteran, a US ambassador and graduate of Yale University.

He had been President Ronald Reagan’s vice-president for two terms and was the only US president to have also served as head of the CIA.

During his first bid for Republican presidential nominee - which he lost to Reagan - the press called him the man with "the biggest resume in America".

Read more here.