WINDSOR, United Kingdom (AFP) — US pastor Michael Curry fired up Britain’s royal wedding on Saturday with some dramatic oratory about the power of love that bemused the royal family but made him a social media hit.

Curry, the first African American leader of the US Episcopal Church, opened his full-throttle sermon in front of Prince Harry and Meghan Markle, in St George’s Chapel at Windsor Castle, by quoting Martin Luther King.

“We must discover the power of love, the redemptive power of love. And when we do that, we will be able to make of this old world a new world,” he said, quoting the US civil rights icon.

With rhetorical flourish, the 65-year-old from Chicago said: “There’s power in love. Don’t underestimate it. Don’t even over-sentimentalise. There is power, power in love.

“I’m talking about some power. Real power. Power to change the world,” said Curry, who heads up the US branch of the Anglican Church and is renowned as an animated and lively preacher.

Members of the royal family looked visibly bemused, not only at the lectern-banging, theatrical style and impassioned content — but also his lengthy, off-script freestyling.

The Archbishop of Canterbury Justin Welby, the leader of the world’s Anglicans who married the happy couple, called it an “extraordinary and powerful sermon”.

In the Windsor streets, crowds of royal fans watching on giant screens reacted with amusement at his 13-and-a-half-minute speech.

“He’s STILL going on!” one man shouted from the crowd.

Kristin Glithero, 45, from nearby Wokingham, told AFP: “I wasn’t expecting this American preacher. It is nice to see something a bit different.

“His message was lovely and the way he delivered it was very powerful, but maybe too long for the British public!”

At a street party in east London, retiree Janet Price, 69, told AFP: “It didn’t go down well with some of the royals, judging by their faces.”

Watching on a giant screen in Leeds, northern England, David Fryer said: “There was one little blip in the proceedings where the archbishop, of wherever he was from, just went on — and on, and on, and on.”

But reactions on social media were far more positive and he was trending worldwide on Twitter.

Fraser Nelson, editor of The Spectator magazine, said he had stolen the show, as maid of honour Pippa Middleton did with her figure-hugging dress at her sister Kate’s 2011 wedding to Prince William, Harry’s brother.

“If Pippa was the unexpected star of Kate’s wedding, Michael Curry is the star of this one. Wonderful, wonderful sermon,” he wrote, offering the preacher a column.

Formula One commentator David Croft said: “I haven’t heard anyone talk as passionately as that about the Power Of Love since Huey Lewis and the News.”

The Times newspaper columnist Hugo Rifkind tweeted: “I love how the entire British royal family is visibly dying of embarrassment because somebody is shouting openly about love at a wedding.”

Curry also referred to slaves singing spirituals about the healing power of love in their captivity.

The ancestors of Doria Ragland — the African American mother of bride Meghan Markle — were slaves, and her surname is that of a slave owner.

“I cannot believe there is a pastor talking about slave spirituals at a dang royal wedding. Hello 21st century,” wrote one Twitter user, @kateyrich.

“This reverend just won the royal wedding,” wrote @nat_sinclair93.

Curry’s sermon also featured lighter moments.

“Two young people fell in love and we all showed up,” he told the crowd, prompting an outburst of laughter.

Finishing up, he turned to the couple and smiled, exclaiming: “We gotta get y’all married.

Additional coverage of the royal wedding on pages 12, 13