WINDSOR, England — British royal weddings aren’t known for their soaring reflections on redemption, justice and civil rights.

But that’s what millions around the world got Saturday when the Most Rev. Michael Bruce Curry quoted a slave song and a speech by slain American civil rights icon Dr. Martin Luther King Jr. during Prince Harry and Meghan Markle’s wedding.

Bishop Michael Bruce Curry gives a reading during the wedding ceremony of Britain's Prince Harry, Duke of Sussex and U.S. actress Meghan Markle in St. George's Chapel, Windsor Castle, in Windsor, on May 19, 2018. Owen Humphreys / AFP - Getty Images

Speaking to an audience that represents the heart of the British establishment, the first African-American to have served as presiding bishop of the Episcopal Church quoted King, leaving some of those gathered apparently amused, surprised or delighted.

“We must discover the power of love, the redemptive power of love,” he said during the animated sermon. "And when we discover that, we will be able to make of this old world a new world.”

Curry, a Chicago native, did not stop with King. His address reflected the philanthropic work pursued by the couple, who with their vows adopted a new official title, the Duke and Duchess of Sussex.

“Oh there’s power in love. There’s power. Not just in its romantic forms," he said.

“I'm talking about some power, real power, power to change the world ... If you don't believe me there were some old slaves in America's South who explained the power of love."

Curry continued, “They sang a spiritual even in the midst of their captivity. It's the one that says there's a balm in Gilead, a healing balm."

Curry departed from prepared remarks distributed ahead of time, directing his sometimes light-hearted conversational comments at the couple sitting before him.

“There’s power in love to help and heal when nothing else can. There’s power in love to lift up and liberate when nothing else will. There’s power in love to show us the way to live.” He went on: “I’m talking about some power, real power, power to change the world.”

“Imagine our governments and countries when love is the way,” he added. “Imagine business and commerce when this love is the way … No child would go to bed hungry in such a world as that. Poverty would become history in such a world as that.”

The bishop joined the dean of Windsor, the Rt. Rev. David Conner, and the Archbishop of Canterbury Justin Welby, who officiated at the service. The Episcopal church is an offshoot of the Church of England and part of the worldwide Anglican Communion.

Saturday's royal wedding also included a gospel choir that sang "Stand by Me," providing an unexpected contrast to the otherwise staid, traditional surroundings.

Curry at one point admitted that he had gone on longer than he'd intended. Nonetheless, the sermon was received with a few smiles and chuckles by the small group of family and friends gathered in the choir, an intimate space in St. George’s Chapel where the altar is located.

Following the ceremony, Curry said the non-verbal communication between the couple spoke volumes.

"The way they looked at each other sent a message that these people are in love," he said.

Elsewhere, his sermon was welcomed as groundbreaking.

“A beautiful service and a beautiful couple. Making my beautiful mixed heritage family’s shoulders stand a little taller,” British lawmaker David Lammy said on Twitter. “Against the odds a great new symbol of all that is still possible and hopeful in modern Britain.”

“We must discover the power of love, the power, the redemptive power of love. And when we discover that we will be able to make of this old world a new world. We will be able to make men better. Love is the only way.” #MLK #RoyalWedding — The King Center (@TheKingCenter) May 19, 2018

MLK is being quoted at a British Royal wedding. Many of the world’s most powerful people of color sitting there, next to the Queen, as a biracial American woman becomes royalty. This is something to witness. #RoyalWedding — Andrea L. Pino (@andreactually) May 19, 2018

Even before marrying Saturday, the new Duchess of Sussex represented a departure for members of the royal family. In addition to being American, she is, in her own words, a "strong, confident mixed-race woman.”

Before getting engaged, she served as a global ambassador for the children’s charity World Vision and traveled with them to Rwanda to learn more about how clean water affects daily life. She also was an advocate for U.N. Women.

Her arrival brings diversity to her new extended family and, while she has been warmly embraced by much of the British public, it has also exposed a quiet strain of racism in U.K. society.

Meghan Markle and Prince Harry leave St. George's Chapel at Windsor Castle after their wedding. Gareth Fuller / Reuters

Curry has been active on social justice issues throughout his ministry, including speaking out on immigration policy and supporting marriage for same-sex couples.

When he was initiated as presiding bishop, he spoke of racial reconciliation, calling it "some of the most difficult work possible."

The bishop has also explained his own family's experience with racism and redemption, saying his father decided to become a part of the Episcopal church after he and his mother had been allowed to drink from the same chalice being passed among white parishioners in racially segregated Ohio.

"He was dumbfounded," Curry told the Associated Press. "Years later he would say he joined the Episcopal Church because he really hadn't imagined that could happen in America. He said, any church where blacks and whites drink out of the same cup knows something about the Gospel I want to be a part of."