As commissioner of the NYPD, Kelly oversees the largest urban police department in the world with close to 40,000 officers in the five boroughs under his command.

The son of a milkman, Kelly was raised on the Upper West Side and in Sunnyside, Queens, and signed up as an NYPD cadet at the age of 19 in 1960. After an interlude in Vietnam as a Marine commander, Kelly returned to the force and steadily progressed through the ranks, serving in 25 different commands (and earning a handful of graduate degrees along the way) before assuming the No. 2 spot under Lee P. Brown, the police commissioner under David Dinkins, in the early 1990s. Dinkins eventually tapped Kelly to replace Brown as police commissioner. But after Rudy Giuliani took office in 1994, he replaced Kelly with Bill Bratton, and Kelly subsequently departed to Haiti at the request of then-President Bill Clinton, who appointed him head of an international police force to restore order in the troubled country. Kelly appeared to be closing the chapter on his lengthy career in public service in 2000 when he accepted an offer from Bear Stearns's Jimmy Cayne to serve as head of the bank's chief of global security. His outlook changed after the events of Sept. 11: When Michael Bloomberg was elected mayor, he managed to persuade Kelly to take up his old post at One Police Plaza, making him the first person to serve non-consecutive terms as New York City police commissioner.

Kelly is often said to be the second-most powerful city official behind Mayor Bloomberg. He is intimately involved in a range of affairs at City Hall and is one of the few public officials with the political capital to operate relatively independently of the billionaire media-mogul-turned-elected-official. Since returning to the job in 2002, Kelly's helped steady a force that suffered a blow to its reputation following embarrassing disclosures about his predecessor, Bernard Kerik. Kelly's also been credited with vastly expanding the department's intelligence capabilities: He established satellite offices in a handful of foreign capitals to gather information about possible threats to the city, built a 1,000-member terror unit, recruited a number of former CIA agents to the force, and stepped up work with national law enforcement agencies to coordinate terrorism-prevention efforts. But being police commissioner also means serving as a lightning rod for criticism, and Kelly's no exception. In 2004, he was roundly criticized for the department's heavy-handed tactics during the 2004 Republican National Convention and Occupy Wall Street protests in 2011.

Kelly has two sons, Jim and Greg; the latter is host of the painfully annoying Good Day, New York and surely appreciate daddy's clout during his 2011 sex scandal. [Image via Getty]