Zohran Mamdani was sworn in as mayor of New York City just after midnight Thursday, taking the oath of office at a historic, decommissioned subway station beneath Manhattan.

Mamdani, a Democrat, became the first Muslim mayor of the nation’s largest city, placing his hand on a Quran as he took the oath. The private ceremony was held at the former City Hall subway station, one of New York’s original stops, renowned for its vaulted ceilings and architectural detail.

“This is truly the honor and the privilege of a lifetime,” Mamdani said in brief remarks following the oath.

The ceremony was administered by New York Attorney General Letitia James, a political ally. In his first comments as mayor, Mamdani described the former station as “a testament to the importance of public transit to the vitality, the health, and the legacy of our city,” and announced the appointment of Mike Flynn as commissioner of the Department of Transportation.

After thanking those in attendance, Mamdani departed the station with a smile, heading up a staircase to street level.

A second, public swearing-in ceremony is scheduled for 1 p.m. Thursday at City Hall and will be administered by U.S. Sen. Bernie Sanders, one of Mamdani’s longtime political inspirations. The ceremony will be followed by a public block party along Broadway’s “Canyon of Heroes,” a stretch famed for ticker-tape parades.

At 34, Mamdani becomes the youngest mayor New York City has had in generations. He is also the city’s first mayor of South Asian descent and the first to have been born in Africa.

Mamdani now takes on one of the most demanding roles in American politics, governing a city of more than 8 million residents while quickly becoming one of the country’s most closely watched political figures.

He campaigned on a platform centered on affordability in one of the world’s most expensive cities, pledging policies that include free child care, fare-free buses, a rent freeze affecting roughly one million apartments, and a pilot program for city-run grocery stores. At the same time, he inherits the everyday responsibilities of running the city, from sanitation and snow removal to transit delays and infrastructure maintenance.

Born in Kampala, Uganda, Mamdani is the son of filmmaker Mira Nair and academic Mahmood Mamdani. His family moved to New York City when he was 7. Growing up in the years following the Sept. 11 attacks, Mamdani has spoken openly about the challenges Muslims faced during that period. He became a U.S. citizen in 2018.

Before becoming mayor, Mamdani worked on local Democratic campaigns and was elected in 2020 to the New York State Assembly, representing parts of Queens.

He and his wife, Rama Duwaji, will move from their rent-stabilized apartment in the outer boroughs into Gracie Mansion, the official mayoral residence on Manhattan’s Upper East Side.

Mamdani takes office as New York City continues its recovery from the COVID-19 pandemic. Violent crime has returned to pre-pandemic levels, tourism has rebounded, and unemployment has fallen back to where it stood before 2020. Still, persistent concerns remain over high prices and rising rents.

He will also navigate a complex relationship with President Donald Trump. During the campaign, Trump threatened to withhold federal funding from New York if Mamdani won and suggested deploying National Guard troops to the city. However, the two later met at the White House in November, a meeting described by aides as cordial.

“I want him to do a great job and will help him do a great job,” Trump said at the time.

Tensions may nonetheless resurface, particularly over immigration policy. Mamdani has also faced criticism from some members of the city’s Jewish community over his past remarks on Israel’s government.

In the weeks since his election, Mamdani has focused on a smooth transition, assembling a team of experienced city officials. Among the early decisions was persuading Police Commissioner Jessica Tisch to remain in her role, a move widely seen as reassuring business leaders and moderates concerned about potential changes to policing policy.

With his administration now underway, Mamdani begins the challenge of turning ambitious promises into policy while governing a city with vast expectations and competing demands.