Hundreds of thousands of people lined the streets of London, with millions more watching on television.

But with the day dedicated to celebrating centuries of Britain’s royal heritage, could a new, modern monarchy welcome, at some point, a LGBTQ+ king or queen?

Here’s what you need to know:

Is Britain ready for a gay, lesbian or transgender monarch?

Overwhelmingly no, say the experts.

“I think in terms of PR, we are not ready for that,” historian and archivist Robert Jarman told Openly.

In his view, the monarchy is a “uniting institution” yet some might see a gay monarch as “divisive”.

There have been many gay and lesbian sovereigns over the years, not least Ludwig II of Bavaria, whose diaries and private letters revealed he was probably gay.

Edward II, who became King of England in 1307, was well-known for showering attention on his male court favourites, particularly Piers Gaveston, the 1st Earl of Cornwall.

But never one who has been openly LGBTQ+.

Author and royal expert Robert Golden agreed with Jarman, but added a note of hope.

In the future, he said, “this probably wouldn’t be a problem at all”.

What happens in other countries?

In 2021, the Dutch prime minister announced that the crown princess, Catharina-Amalia, 19, who has not made any comments concerning her personal life, would have the right to marry a same-sex partner without giving up the throne.

“The cabinet … does not see that an heir to the throne or the King should abdicate if he/she would like to marry a partner of the same sex,” Prime Minister Mark Rutte wrote to parliament at the time.

The question arose after books argued that the country’s rules excluded the possibility of a same-sex royal couple.

The Netherlands was the first country to legalise gay marriage in 2001.

Weeks later, the Swedish Marshal of the Realm, responsible for the country’s royal court, also said that a prince or princess in a same-sex union could ascend to the throne.

Could Britain follow suit?

Technically, yes, but there could be constitutional challenges, say royal experts.

Questions would arise about the status of the king or queen as head of the Church of England, which currently does not allow same-sex marriages in its churches.

Golden said he thought a gay, lesbian or trans king or queen might still be a “no no”, but was unsure what the future might hold.

“In 40 years’ time, things in society might have changed beyond all recognition,” he added.

For veteran human rights campaigner and arch republican, Peter Tatchell, however, the whole notion of being ruled by a monarch, LGBTQ+ or otherwise, is “not compatible with a modern democracy”.

“The idea that the highest public office in the land, or head of state, should just fall to a person via inheritance from a very wealthy privileged family is out of step with democratic and meritocratic ideals,” Tatchell said.

Reporting by Hugo Greenhalgh.

GAY TIMES and Openly/Thomson Reuters Foundation are working together to deliver leading LGBTQ+ news to a global audience.