Sir Paul Stephenson was named Metropolitan Police Commissioner in January 2009, taking Britain's top police job as debate continued in City Hall over the influence of politics on policing.
Bus services were suspended and roads and schools were closed during London's heaviest snowfall for a decade on 2 February.
London taxi driver John Worboys, from Rotherhithe, east London, was jailed indefinitely in April after being found guilty of drugging and sexually assaulting a series of female passengers in his cab.
Green campaigners and anti-capitalist protesters clashed with police at the G20 summit in the City of London on 1 April. Newspaper seller Ian Tomlinson died after allegedly being pushed over by a police officer following the protests.
Steven Barker, Tracey Connelly and Jason Owens were jailed in May for causing or allowing the death of Connelly's son, Baby Peter. The 17-month-old boy sustained more than 50 injuries in Haringey, north London.
Three children and three adults died in fire at 12-storey tower block Lakanal House in Camberwell, south London, in July. After the fire it emerged Southwark Council had failed to carry out a legally required fire risk assessment.
The first nine bendy buses were taken out of commission in July as London Mayor Boris Johnson began to carry out his election pledge to scrap the "writhing whales of the road".
A total of 2,400 members of the public stood on Trafalgar Square's fourth plinth in Antony Gormley's One and Other project. They included Brian Capaloff who highlighted the plight of Linda Carty, a British grandmother on death row in America.
Oxford Circus pedestrian crossing in the West End was redesigned in November to allow shoppers to cross diagonally in an "X" as well as straight ahead, inspired by crossings in Tokyo.
Battle of Britain hero Sir Keith Park was honoured with a temporary statue in Trafalgar Square, following a long-running campaign to honour the World War II hero. A permanent memorial will be erected in Waterloo Place in 2010.
The London 2012 Olympic Village continued to take shape in Stratford, east London, as the roof of the Aquatics Centre was put in place in November. Construction of Games facilities remains on schedule and on budget, the Olympic Delivery Authority said.
Mehmet Goren was jailed for a minimum of 22 years for murdering his 15-year-old daughter Tulay in a so-called honour killing. The schoolgirl's body was never found after she disappeared from their home in Woodford Green, north London, in January 1999.