In the hushed atmosphere of a south London mosque, a dozen Muslims of all ages wait to sign a book of condolence for Queen Elizabeth II at an interfaith ceremony.

Unlike when she ascended the throne in 1952, she died last week with Britain, which is now multicultural and multireligious, and increasingly secular.

This decades-long transition seems to have left the country’s growing Muslim population with a strong appreciation for Britain’s longest-serving monarch.

“I’m a first-generation Muslim in this country,” said Danial Saeed, a demure 19-year-old who wears fogged-up glasses and a face mask.

“We must practice our faith in this country under the protection of our Queen.”

The British head of state remains a figurehead of the Anglican communion, bearing the centuries-old title of Defender of the Faith and Supreme Governor of the Church of England.

At Charles’ future formal coronation, Archbishop of Canterbury Justin Welby will anoint him with holy oil and bless the new king.

Although the monarchy is deeply rooted in Christianity, Charles has previously insisted that as he ascends to the throne he is committed to defending all faiths.

In his inaugural address last week, he noted that British society had “become one of many cultures and many faiths” during his mother’s record-breaking 70-year reign.

But in a sign of the delicate balancing act required in his new role, he also touted “the sovereign’s special relationship and responsibility to the Church of England.”

He added his own Anglican faith was “deeply rooted”.

At the huge Bait-ul-Futuh Mosque in south London, Rafiq Hayat, head of the organization Ahmadiyya Muslim Community, said there was a seamless transition in relations with Charles III.

“Our loyalty to the King will be as strong as it is to Her Majesty the Queen,” he told AFP.

Hayat argued that Charles had “a great relationship with the Muslim world,” noting that he had a history of praising the teachings of Islam and reciting verses from the Koran.

“I think he feels Islam sits very well with Christianity and other world religions,” he said.

On Friday, the new monarch will receive representatives of the main religions practiced in Britain at Buckingham Palace, a further sign of his intention to go beyond the Christian faith groups.

The king brought forward the audience so Chief Rabbi Ephraim Mirvis could return home in time for the Jewish Sabbath, which begins Friday at 17:59 GMT.

A source close to the Chief Rabbi told BBC News the decision to bring the event forward was an “amazing gesture of respect and thoughtfulness”.

Ian Bradley, a professor of theology at the University of St Andrews, said the British monarch’s role is to “bind the nation together in all sorts of ways, not least in terms of faith”.

And that doesn’t have to be limited to Christianity, he said, noting that some of the strongest supporters of the monarchy are from minorities in Britain.

Rami Ranger, President of the British Sikh Association, said the late Queen brought “an immense sense of security” to his community.

“She was above partisan politics and could unite the nation regardless of race, religion and color,” he added.

Bradley believes the British monarchy has a broader “spiritual dimension” that lends a “spiritual heart” to the country’s so-called unwritten constitution, which has evolved over centuries.

“It’s very different from France…it’s a very clearly secular state and has a secular constitution,” he added.

“We’re mostly a post-Christian secular nation now, but a lot of people still like that the monarchy still has that religious aura.”

Echoing Hayat, Bradley points out that while Charles is a devout Christian, he is “very interested in Islam (and) spirituality in general.”

Just as the new king’s well-known stances on environmental issues resonate particularly with young people, his openness to religion could resonate with his subjects in Britain and beyond.

Among Christians he has shown a special fondness for the Orthodox faith and has undertaken several retreats in monasteries on Mount Athos in Greece.

Meanwhile, he also touched Britain’s Jewish community by visiting Israel – which his late mother never did – although it was not an official visit.

Charles also commissioned portraits of Holocaust survivors, a gesture of remembrance that was also appreciated.

For Hayat, the new king is well positioned when it comes to speaking about faith.

“When he speaks, people listen,” he said.

“This will be a very important message that he will send to the whole world that Islam is a religion of peace and that Islam is not associated with terrorism.

“It will make a big difference in the relationship between the Muslim world and the Christian world and the Jewish world.”