WINDSOR, England (Reuters) - African-American bishop Michael Curry electrified the wedding of Prince Harry and Meghan Markle with a barnstorming sermon on the power of love that won smiles in the ancient British chapel and praise across the internet.

Curry, the first black head of the Episcopal Church in the United States, started by quoting civil rights hero Dr Martin Luther King and powered on citing spirituals, medieval poetry and the experiences of slaves in the American south.

“There’s power in love. Don’t underestimate it. Don’t even over-sentimentalise it ... If you don’t believe me, think about a time when you first fell in love,” he said at the start of an address that jolted the congregation after a long period of serene choral music and ceremony.

By the end, he was referring to Harry and Meghan as “my brother, my sister,” and telling them “God love you, God bless you” before the opening notes of the soul standard “Stand By Me” started up.

Meghan smiled throughout as Harry looked on intently.

“It was a moment for African-Americans. It was like we were at church. It was the word that love conquers all,” said Karen Long from Houston, Texas, who came to Windsor with her sister and friend, all dressed as bridesmaids.

“It was a perfect blend between her culture and the royal culture. As an African-American woman, it was made in heaven,” she said.

The reaction online was overwhelmingly positive.

“Quoting Dr. Martin Luther King from the altar of a British royal wedding. This sermon by Rev Michael Bruce Curry is very American, very boisterous, very passionate. Love it,” said New York Times reporter Katie Rosman on Twitter.

The Most Rev Bishop Michael Curry, primate of the Episcopal Church, gives an address during the wedding of Prince Harry and Meghan Markle in St George's Chapel at Windsor Castle in Windsor, Britain, May 19, 2018. Owen Humphreys/Pool via REUTERS

Karen Attiah, Global Opinions Editor of the Washington Post, called the whole wedding “an overt celebration of black American culture”.

“I wrote back in the fall that I didn’t think Meghan Markle was going to be very outspoken about race once she married into the royal family. Maybe she will prove me wrong?,” Attiah tweeted.

“DISCOVER LOVE”

Members of the royal family, including Harry’s brother Prince William, could be seen on TV smiling during the lengthy address. Meghan’s mother, Doria Ragland, nodded several times as the bishop spoke.

Some commentators took to Twitter to point out the facial reactions in the chapel to the Bishop’s sermon. In particular, a close-up of the Queen’s granddaughter, Zara, with her mouth open became a focus for social media. Harry’s cousin Princess Beatrice was spotted giggling.

Barely glancing at the transcript of his speech in front of him, Curry talked directly to a congregation that included Queen Elizabeth and celebrities such as Oprah Winfrey, Elton John and David Beckham.

Leaving the prepared text of his speech far behind him, he told them that love was not just for young couples but part of God’s plan with the power to change the world.

“We will let justice roll down like a mighty stream and righteousness like an ever-flowing brook. When love is the way poverty will become history,” he said channeling Dr King channeling the Bible in a rare nod to politics during a highly orchestrated British state occasion.

Curry grasped the lectern, then waved his arms to punctuate his points, shaking the candles in front of him. “Love God, love your neighbor. And while you’re at it, love yourself,” he said in a sermon that used the world “love” just short of 70 times.

At one point, realizing that he had been going on for a while, he paused and promised: “With this I’ll sit down. We’ve gotta get y’all married.”

The Episcopal Church - the U.S. arm of the Anglican Communion which also includes the Church of England, headed by the queen – has taken a strongly liberal stand on social issues, including gay marriage, which it allows.

Curry was born in Chicago in 1953 and went on to become the bishop of North Carolina. At his installation as the head of the Episcopal church in 2015, he called for economic and racial unity at a time of rising racial tensions.

In 2016 he said he lamented the decision by the wider Anglican Communion to slap sanctions on the U.S. church over its support of gay marriage.