More than one million people lined the route of the Tour de France as it started in England for the first time in its 104-year history.
The 189 cyclists left London for finish line at Canterbury
Spectators cheered the 189 riders as they left Greenwich, south London, and rode out of the city towards Kent.
The 203km first leg of the race finished in Canterbury.
About 4,500 Metropolitan police were on duty over the weekend in addition to officers from Kent and a contingent from France.
On Saturday it was thought that more than a million spectators flocked to the streets of central London to watch the riders take part in the Tour's time trials or Prologue.
Fabian Cancellara, of Switzerland, clocked the fastest time while Londoner and Olympic pursuit champion Bradley Wiggins came in fourth.
Riders left The Mall in central London at 1030 BST on Sunday pausing briefly at Tower Bridge.
The race officially began at 1100 BST as the cyclists rode through Greenwich crossing the meridian line.
Mayor Ken Livingstone described the event as a "phenomenal success" and said it had generated more than £115m for the city.
"Not only has our city successfully hosted the world's biggest annual sporting event, but we have set out a stall for a cycling renaissance in London."
Millbank up to Lambeth Bridge
Hyde Park Corner
Grosvenor Place north of Hobart Place
Park Lane south of Curzon Gate
He added: "This demonstrates London's ability to host top-class sporting fixtures and promote them to a world-wide audience."
To manage the crowds Metropolitan Police officers were aided by 1,800 officers from Kent along with a team of 45 French officers.
Metropolitan Police Assistant Commissioner Tarique Ghaffur said: "This weekend is an excellent example of the skills, professionalism and partnership working that we can deliver in order to provide a safe and successful Olympic and Paralympic Games in 2012."
Giant screens were also put up in some places along the route.
Whitehall, Parliament Street and Victoria Embankment, will be closed throughout the weekend.
Other roads which will be closed are: Kensington Road (east of the Royal Albert Hall), South Carriage Drive, West Carriage Drive, Serpentine Road, Pall Mall, Pall Mall East, Haymarket south of Charles II Street, Cockspur Street, Strand, Trafalgar Square, Charing Cross Road south of Cambridge Circus and Northumberland Avenue.