As guests filed into Westminster Abbey for the coronation of King Charles III, a young man wearing a ceremonial robe of blue and gold beneath a glinting chain of office walked up the central aisle and took a prime seat by the choir.

He was the Right Worshipful Lord Mayor of Westminister. And he was extremely nervous. In the car, he’d combed his beard and checked his outfit several times before making his grand entrance.

“You’re in front of millions — you can’t afford to put a step wrong,” Hamza Taouzzale recalled recently.

Just 22 at the time of his appointment as lord mayor last year, he is the youngest ever, and the first Muslim, to hold the ceremonial role, which serves as a sort of good-will ambassador for Westminster and its residents. He represents the area, which covers much of central London, at civic events with all the pomp and protocol that comes with the title, which was created by Queen Elizabeth II by letters patent in 1966.

From the moment he was sworn in, Mr. Taouzzale, who grew up in a single-parent household in public housing in the British capital, was catapulted into a world of power and privilege.

In addition to a stipend of 24,000 pounds ($30,600), he was given a capacious office; a researcher; a diary manager; and a macebearer, who doubled as his chauffeur and etiquette guide for high-profile public engagements, many at Buckingham Palace.

The first funeral he attended in his life? Queen Elizabeth’s in September.

“You get to see a range of different lifestyles,” Mr. Taouzzale said. “Westminster is a tale of two cities,” he added. “You have extreme wealth and extreme poverty.”

Westminster’s borders include some of Britain’s most famous landmarks, like the Houses of Parliament, the Abbey and Buckingham Palace. It’s also home to more than 250,000 residents, living in both some of the nation’s most expensive real estate as well as in public housing, where many rely on food banks — a contrast that the opposition Labour Party has called a “crisis of inequality.”

Mr. Taouzzale still lives in the apartment he grew up in. “My grandmother came to Westminster in her early 20s from Morocco,” he said. “My mother grew up on this estate, and I was born and raised here. It’s a big part of who I am.”

Active in local politics since 16, he was elected, at 18, as a Labour member of the Westminster City Council, before earning both a B.A. and an M.A. in politics. He hopes to use his council seat as a steppingstone to national office, with an eye on entering Parliament.

The council, whose more than 50 members have responsibility for a number of government services including council housing, trash collection and traffic, chooses the lord mayor for each one-year term.

Mr. Taouzzale said he was surprised to be chosen, as the post usually goes to councilors in the autumn of their careers.

“I think it was a statement: a sign that the City of Westminster is moving forward,” he said. “Before me there wasn’t a single lord mayor who wasn’t from an English or white background.”

He added, “I think it was a sign that the City is becoming more progressive.”

Mr. Taouzzale said he made a point of attending events in his home district, Westminster North, since residents in that densely packed, lower-income area felt it was always overlooked. “Growing up, I had no idea who the lord mayor was — I had never seen them. I wanted to change that.”

Most lord mayors have had a partner or spouse to act as their official consort. Mr. Taouzzale took his mother, aunt and grandmother to big events at Buckingham Palace; younger siblings, friends and fellow councilors accompanied him to other appearances.

“I did absolutely anything and everything,” he said. “Even if I didn’t feel like it that day, even the unglamorous stuff.”

Mr. Taouzzale’s formal engagements commenced with the Platinum Jubilee last June, celebrating Queen Elizabeth’s 70 years on the throne. At an evening concert, he found himself seated in the royal box directly in front of Boris Johnson, then the prime minister, and just behind the Prince and Princess of Wales.

It was a pinch-me moment. Mr. Taouzzale was taking surreptitious photos of the global figures around him and the crowds below as a personal memento, or a kind of proof of attendance, when someone tapped him lightly on the shoulder and whispered: “You don’t have to take pictures, you know. You’ll be on television.”

It often felt, Mr. Taouzzale said, as if he was leading a surreal double life.

“I would go to a really posh, fancy dinner at a members’ club or a private residence, where everyone would seem to already know each other, they’re in this circle, and then I’d go home and be like, ‘Wait a minute, did I really just do that?’”

Amid all the pomp and ceremony — at most events, he was the highest-ranking person in attendance, ahead of even generals, and the last to enter a room (“really weird,” he said) — came occasional etiquette snags.

“What fork or knife to use was tricky at first,” Mr. Taouzzale said. “I never used to have more than one fork or one knife on the table, and suddenly I had three of each. It was like, what do I do?”

The months as lord mayor went by in a blur. He oversaw the cutting of Britain’s national Christmas tree in Norway and switched on its lights in Trafalgar Square alongside Sadiq Khan, London’s mayor.

“Hamza Taouzzale’s recent term as Lord Mayor of Westminster is emblematic of the strength of London’s diversity,” Mr. Khan said.

Being the first Muslim to hold the role required some negotiating, as part of the lord mayor’s job includes speaking regularly at the Abbey, an Anglican church.

“Whenever I did a reading at the Abbey, we had to spend a lot of time with the dean to figure out what the right reading was,” he said. “I am a devout Muslim, I’m not going to hide my faith to read something that I don’t agree with, or don’t think is right. So we always had to find a verse somewhere in the Bible, or a reading, that would match my religious understanding.”

Now that the new lord mayor has been sworn in — Mr. Taouzzale has had to return the robes, the office and the car with its coveted WE 1 license plate — he is thinking of the future and looking for a job, as the councilor position is part-time only, paying about $11,500.

He hopes his term as lord mayor motivates Westminster’s next generation.

“Growing up in my area, I didn’t feel like we were allowed to have any positive aspirations. They were shut down quite early on,” he said. “If you had a decent job, people would be like ‘oh, you’re lucky. Oh, you’re lucky you went to university.’ Why isn’t that the bare minimum? Why isn’t it the standard?”

He added: “Hopefully, I’ve been able to inspire people. I hope they can say, ‘well, if Hamza’s done it, I can do that as well.’”