Rudy Giuliani is one of the great mayors in the history of New York City.

In 1989, Giuliani ran for mayor of New York City as a Republican against Democrat David Dinkins.  He lost by a razor-thin margin in one of the closest mayoral elections in New York City history, and Dinkins became the city's first black mayor.  Four years later, in 1993, Giuliani again challenged Dinkins. With more than one million New Yorkers on welfare, crime rates skyrocketing and an ever-worsening crack cocaine epidemic plaguing the city, the mild-mannered Dinkins had fallen out of favour and a tough-on-crime prosecutor appeared—to many—to be exactly what the city needed. Giuliani won the election and took office as New York City's 107th mayor on January 1, 1994.

Giuliani set out to tackle New York's problems with a single-mindedness that bordered on ruthlessness. In his first two years in office, his policies helped reduce serious crime by one-third and cut the city's murder rate in half. Police shootings fell by 40 percent and incidents of violence in city jails, once a seemingly insurmountable problem, virtually disappeared by the end of his first term, dropping by 95 percent. Giuliani's highly successful "welfare-to-work" initiative helped more than 600,000 New Yorkers land employment and achieve self-sufficiency.

He won re-election by a landslide in 1997 but just as Giuliani appeared to be heading into retirement, he was suddenly thrust into the international spotlight by a tragedy that shocked the world and came to define his public career.  On September 11, 2001, al-Qaeda hijacked two commercial passenger airliners and crashed them into the twin towers of the World Trade Center in Manhattan.  Both towers collapsed within hours and 2,752 people perished from the attacks. Giuliani's leadership during the city's moment of crisis inspired many.

Arriving on the scene within minutes of the second plane crash, Giuliani coordinated rescue operations that saved as many as 20,000 lives and emerged as the national voice of reassurance and consolation. "Tomorrow New York is going to be here," a sombre but resolved Giuliani announced to the city, the nation and the world. "And we're going to rebuild, and we're going to be stronger than we were before... I want the people of New York to be an example to the rest of the country, and the rest of the world, that terrorism can't stop us."

In 2008, he ran for the Republican presidential nomination, but despite being an early frontrunner his campaign didn't generate enough momentum and he dropped out after the Florida primary. 

Giuliani was named Time magazine's Person of the Year for 2001, and was honorarily knighted in 2002 by the UK's Queen Elizabeth II.