New York City Mayor-elect Bill de Blasio, an unabashed liberal who campaigned to keep down crime and continue the city's prosperity while reducing the gap between rich and poor, was sworn in at a ceremony at his home just after midnight.
De Blasio's formal inauguration ceremony will take place at noon on Wednesday at City Hall, where former U.S. President Bill Clinton will administer the oath of office using a Bible once owned by Franklin Delano Roosevelt.
Mayor Michael Bloomberg, who led the city through its response to the attacks of September 11, 2001, and the recession six years later, and whose policies have been credited with making the city safer, greener and more livable, is leaving City Hall after 12 years.
Bloomberg plans to take a two-week vacation in Hawaii and New Zealand with his longtime girlfriend, Diana Taylor. Then, the billionaire, who has homes in Bermuda and London, has said he will focus on his charitable foundation, Bloomberg Philanthropies, and remain active in public health, gun control and government innovation.
On the campaign trail, de Blasio presented himself as an anti-Bloomberg, decrying the "tale of two cities" that emerged as New York shed its reputation, from the 1970s and 1980s, as a gritty and dangerous place.
After a resounding victory in November with more than 70 percent of the vote, de Blasio has pledged to confront the affordability gap that has led to those in the middle and at the bottom of the economic ladder struggling to pay for basic services such as housing and mass transit.
Over the last decade, as the city prospered, apartment rents in New York City rose about 44 percent and the cost of a monthly Metro card jumped 60 percent.
De Blasio has made some major promises, and his critics are likely to quickly seize on his ability to deliver.
His signature proposal of creating universal access to pre-Kindergarten and middle school after-school programs depends on the approval - by state lawmakers and Governor Andrew Cuomo - of an income tax increase on the city's highest earners. Cooperation from Albany is far from assured.
De Blasio has also pledged to improve police and community relations to continue New York's historic drop in crime, as well as to fight the closure of community hospitals.
While Bloomberg has left the city with no budget deficit for the current fiscal year, contracts for all of the public sector unions have expired. In a press conference on Tuesday afternoon, de Blasio said he hoped to have the new contracts in place within a year.
De Blasio began his career in government working under David Dinkins, the city's first black mayor who was elected in 1986 and was the last Democrat to hold the post. In 2000, when former U.S. first lady Hillary Clinton ran for U.S. senator in New York state, de Blasio was her campaign manager.
He went on to serve two terms on the New York City Council and four years ago was elected public advocate - a citywide office with a budget of just $2 million that is generally seen as a springboard for the job of mayor.
On Wednesday, the city's new comptroller, Scott Stringer, and its new public advocate, Letitia James, will also be sworn in. Both are Democrats and close allies of de Blasio.