Eight years with Barack Obama
Pete Souza became chief official White House photographer in January 2009, having spent four years intermittently documenting Barack Obama's rise from senator for Illinois to president of the United States of America.
Mr Souza spent about 10 to 12 hours a day in Mr Obama's presence, sometimes for seven days a week. He clocked up just under two million photographs over the eight-year presidency.
"You realise that documenting the president for history is an all-consuming, 24/7, always-on-call, no-vacation, no-sick-days, BlackBerry-always-vibrating kind of job," he says.
Here is a selection of his best shots, painting a portrait of Barack Obama as both playful and serious, as a family man with a natural affinity for meeting his public.
On 20 January 2009, in a goods lift on the way to an inaugural ball, the president drapes his jacket over his wife Michelle's shoulders to keep her warm.
"They had a semi-private moment as staff member and Secret Service agents tried not to look," remembers Souza.
After the party at the White House, Mr Obama adjusts his collar while heading back to his private residence.
Pete Souza's pictures of Mr Obama cast him very much as a family man. He attended one of his daughter Sasha's basketball games. The two coaches could not make the match.
"The president and his then personal aide, Reggie Love, filled in as coaches for this game one Saturday," Mr Souza remembers. "Here they react, along with Sasha's team-mates, during the game."
The first three months of 2010 focused on the passing of the Affordable Care Act, until it went through on 21 March.
A huge snowstorm in the midst of this period shut down the government for days, and Mr Obama seized the opportunity to play with Sasha and his other daughter, Malia.
Mr Obama greets children at a nursery in Bethesda, Maryland.
He had travelled to Sasha's school for her end-of-year ceremony and spotted the kids next door looking out of the window at him.
He also had older fans. Here he listens to Thelma "Maxine" Pippen McNair after signing HR 360, which provided for a Congressional gold medal to commemorate the four young African-American victims of the 1963 bombing of the Sixteenth Street Baptist Church in Birmingham, Alabama.
Mrs McNair's daughter Denise was one of the victims.
At the G7 summit in Krun, Germany, President Obama talks to German Chancellor Angela Merkel.
The pair formed a close bond over the eight years that he was in office.
Mr Souza took many pictures of the president playing with children.
Here, he lifts up Ella Rhodes, daughter of Deputy National Security Advisor Ben Rhodes, as she dressed up for Halloween.
Obama also met the more well-known Prince George at his Kensington Palace home.
Obama: An Intimate Portrait by Pete Souza is published by Allen Lane.