Since leaving public office he has been campaigning against poverty and he now says his charity is helping a younger generation which he describes as “austerity’s children”.
He praised Prince William’s involvement in helping people who “through no fault of their own need help to get back on their feet”.
And he welcomed the way that the prince, through Homewards, was changing perceptions about people who become homeless.
“He’s changing people’s views, so that you’ve got to think of a homeless person as an individual who has potential, who if given the proper chance can make something of their lives, and not as someone to be discounted as a down and out.
“It’s someone who has got potential talent, and if you can find a way of developing that talent, you can make a real difference to their lives, and they can make a real difference to the life of the community. So this is an investment in all our future,” said Brown.
“We’re seeing something big here,” added Brown, that familiar voice now in an unexpected royal partnership.
It was even more of a surprise for a handful of bystanders outside the low-key visit, who looked up to see a former prime minister and then a purposeful Prince of Wales, heading towards his car.