1981 Trump talks on a car phone in a limo in New York City. “It looks like he’s running for President in there,” Benson said. “There’s a bit of control there ... People walking about but he’s in the limo.”

The first time legendary photographer Harry Benson saw a million dollars, in cash, it was in Donald Trump’s arms. "It was always on the spur of the moment," says Benson. It was 1990 and he was in Atlantic City for the grand opening of the now-shuttered Trump Taj Mahal casino resort.

“You know, I can go over there and get a million dollars,” Benson recalled Trump saying. Benson replied, “Donald, I’ve never seen a million dollars in my life.” Trump said, “You’ve got it.”

That’s how it’s always been between these two: the famed Scottish photographer who chronicled the Beatles on their inaugural trip to America in 1964 and has turned his lens to every U.S. president since Dwight Eisenhower, and the camera-ready real estate mogul who found his way into politics. Benson has photographed Trump over nearly 40 years, and his portfolio provides perhaps the clearest look at Trump’s rise and reality.

1987 Harry Benson photographing Trump on the way to Atlantic City. Jonathan Delano

Ahead of the GOP convention in Cleveland, held from July 18 to 21, TIME revisited Benson's archive. It shows the transformation from businessman during the stock market boomtimes to celebrity to, now, presumptive Republican presidential nominee.

After a recent shoot, Benson sat down with TIME to talk about his decades around Trump. “The man I met the other day there, that was him from the beginning,” Benson said. “And if you come up with an idea, he jumps on it right away … like going in and getting the money.”

That’s a key theme throughout Benson’s photography. There’s spontaneity and honesty. “I hate studio pictures because they’re not real,” he adds. “I want people to be what they think they are, not what I think they are.” He lets his subjects do what they want, and Trump always has: he’s chosen to show off his wives and his rides, his buildings and his gold.

Benson remembers photographing Trump with each of his wives. The first time he met and photographed Ivana, he wanted them in their bedroom and asked them to dance. And they did. “She could dance,” Benson recalls, “but he was a bit slow.” With Marla, Trump’s second wife, Benson photographed the two in robes at the Trump International Hotel & Tower in Manhattan. In 2014, Trump and Melania are at home on a gold table. Her legs are across him. “Donald was very proud of her,” he says.

Recalling these moments and more, Benson said, “I must say, Donald Trump, it’s always been fun.”

Harry Benson is an award-winning photographer known for chronicling the world's most fascinating figures. This fall the documentary Harry Benson : Shoot First will be released by Magnolia Pictures. You can see more of his work here .

Paul Moakley , who edited this photo essay, is TIME’s Deputy Director of Photography and Visual Enterprise. Follow him on Instagram @paulmoakley .

Andrew Katz is TIME’s International Multimedia Editor. Follow him on Instagram @katzandrew .