Image source, Reuters

Simpson shares some inside jokes, including an evening singing Don't Cry For Me Argentina from the musical Evita, to the laughter of his listeners.

He echoed Mulroney's praise of Bush Sr's political accomplishments and his best aspects - including "great competitiveness", and "raw courage".

But he eventually returned to Bush Sr's "very serious flaw": a good joke.

"He loved a good joke, the richer the better," Simpson says. "And he'd throw his head back and give that great laugh. But he never, ever could remember a punchline."

"So the punchline for George HW Bush is this: you would've wanted him on your side. He never lost his sense of humour.

"Humour is the universal solvent against the abrasive elements of life. He never hated anyone. He knew what his mother and my mother always knew: hatred corrodes the container it's carried in."

Mulroney listed many of Bush Sr's political achievements, including negotiating Nafta, the Americans with Disabilities Act and the 1990 Clean Air Act.

"There's a word for this: it's called leadership."

"And let me tell you, that when George Bush was president of the United States of America, every single head of government in the world knew that they were dealing with a gentleman, a genuine leader, one who was distinguished, resolute and brave."

Former Wyoming Senator Alan Simpson is now delivering the third tribute to Bush.

He said Bush had a simple credo: "What would we do without family and friends?"

During a difficult time for Simpson, he says Bush invited him and his wife to spend the weekend with his family.

"At that time his popularity rating was 93%. Mine was 0.93%."

"I said, George, I am not unmindful as to what you are doing. You are propping up your old wounded duck pal.

"While you're at the top of your game, you reach out to me while I'm tangled in rich controversy and taking my lumps.

"And he said, yep. There were staff members, Al, who told me not to do this. But Al, this is about friendship and loyalty."

During a visit to the Bush home in Maine, Mulroney describes how Bush Sr once told him he felt everything was "perfect" in his life.

"Barbara and I could not have asked for better lives. We are truly happy and truly at peace."

Mulroney concluded his tribute with a few poetic lines that he said "spoke to the true nature of George Bush and his love of his wonderful family".

"There are wooden ships, there are sailing ships, there are ships that sail the sea, but the best ships are friendships, and may they always be."

Image source, EPA

To the laughter of the crowd, Canadian Prime Minister Brian Mulroney relates a Bush anecdote from an international summit.

He says Bush used to diligently take notes at international meetings. And at a Nato summit in Brussels the president continued to scribble notes during an interminable speech by the prime minister of Iceland, which was only cut off when the secretary general firmly decreed a coffee break.

Afterwards, Bush put down his pen and told Mulroney: "Brian, I've just learned the fundamental principle of international affairs."

"What's that, George?" Mulroney replies.

"The smaller the country the longer the speech," says Bush.

Former Canadian Prime Minister Brian Mulroney began the second eulogy with fulsome tribute.

"I believe it will be said that in the life of this country, the United States, which is in my judgement the greatest democratic republic that God has ever placed on the face of this earth, I believe it will be said that no occupant of the Oval Office was more courageous, more principled and more honourable than George Herbert Walker Bush."

This is that uncomfortable moment when the Trumps greeted the Obamas.

As the choir sings The King of Love My Shepherd Is, former first daughter Jenna Bush Hager, granddaughter of Bush Sr, makes her way to the front of the cathedral for the second reading.

This excerpt is from Revelation 21:1-4, 23-25, describing the new heaven on earth in Jerusalem.

Jon Meacham also described the late president's love for his wife, Barbara Bush. Her nicknames included "silver fox" and "the enforcer".

"He was the only boy she ever kissed," Meacham said of their relationship. "Her children, Mrs Bush liked to say, always wanted to throw up when they heard that."

He detailed a letter a young George HW Bush had written to her during the war: "I love you with all my heart. How lucky our children will be to have a mother like you."

Image source, AFP

Image source, EPA

Jon Meacham concludes his tribute pondering why Bush Sr survived his WW2 brush with death.

"And so we ask as we commend his soul to God, why him? Why was he spared? The workings of Providence are mysterious but this much is clear…

"The George Herbert Walker Bush who survived that fiery fall into the waters of the Pacific three quarters of a century ago made our lives and the lives of nations freer, better warmer and nobler.

"That was his mission. That was his heartbeat."

"And if we listen closely enough, we can hear that heartbeat even now, for it's the heartbeat of a lion. A lion who not only led us, but loved us."

"That's why him. That's why he was spared."

Jon Meacham makes the crowd laugh as he recalls Bush Sr's not-always-eloquent way with words, including such lines as:

"We're enjoying sluggish times, but we're not enjoying them very much."

And:

"It's no exaggeration to say that the undecideds could go one way or another."

The Bush family chortle as the historian tells how Bush once accidentally asked a shop mannequin for its vote.

"President Bush spoke with those big strong hands, making fists to underscore points," presidential historian Jon Meacham said in his tribute.

"A master of what Franklin Roosevelt called the science of human relationships, he believed that to whom much is given, much is expected."

"And because life gave him so much, he gave back again and again and again."

Meacham described Bush Sr's efforts regarding the Cold War, partisanship in Washington, and other political battles.

Historian Jon Meacham began his eulogy by telling of how the former president had served as a US Navy pilot in World War Two, surviving after his plane was shot down by Japanese forces over the Pacific.

"His life was a perennial effort to prove himself worthy of his salvation on that distant morning," the historian said.

Bush's granddaughters, Lauren Bush Lauren and Ashley Walker Bush, began the funeral by reading passages from the Book of Isaiah 60:1-5, about the glory of Zion.

The former president's casket has been set down at the front of the National Cathedral.

The choir leads the mourners in singing the hymn Praise, My Soul, the King of Heaven.

After a prayer from Reverend Randolph Marshall Hollerith, Bush Sr's granddaughters Lauren Bush Lauren and Ashley Walker Bush will begin the first reading.

Image source, BRENDAN SMIALOWSKI/AFP/Getty Images

Before taking his seat at the front of the cathedral, former President George W Bush shook hands with the row of presidential figures across the aisle.

President Donald Trump has ordered many government offices to close as the country mourns the death of its former president.

Here's what's been shut for the day via Trump's executive order:

• Some National Parks
• US Post offices
• The New York Stock Exchange
• Congress
• The Supreme Court
• All non-essential federal offices

Texas, the former president's home state, has also shut down its government offices.

On Twitter, #NationalDayofMourning, #GeorgeHWBushFuneral and National Cathedral are trending.

Thousands are sharing posts and photos in memory of the 41st president.

After a few words from the presiding clergy, the casket of Bush Sr has been carried into the cathedral.

The Bush family has also arrived, walking in as the choir resumes singing.