A Pendolino 125mph tilting train has knocked 15 minutes off the record time for a London-Manchester journey, arriving in one hour, 53 minutes.
Tony Blair and Sir Richard Branson launch 125mph Pendolino
Prime Minister Tony Blair joined Virgin Trains boss Sir Richard Branson at London's Euston Station to mark the entry of tilting trains into service.
Improved passenger services will start in a week's time
The new schedule will cut the two hour 41 minute journey between London and Manchester by 35 minutes.
Mr Blair said: "Today is a great day for the whole of the rail network in this country.
"For the first time in many years along with the Channel Tunnel rail link, we have actually got new investment yielding a result for the rail network in this country and that is a tremendous achievement.
"If we can get the right technology and investment in, we can actually shorten the journey times between our major cities and bring the country with a greater sense of mobility together".
FACTS ABOUT TILTING TRAINS
British Rail tried and failed to launch tilting trains in the 1980s
The first Pendolino train was launched in July 2002
The trains were originally forced to run in non-tilt mode
Features on the trains include video and audio entertainment
Virgin Trains claim journey times will soon be cut by 25%
The work on upgrading the line from London Euston to Manchester is finished, but completing improvements to Scotland will take another year.
The project to rebuild the West Coast Main Line has been a tortured tale of slipping deadlines and spiralling budgets.
British Rail originally attempted to launch a tilting train under the title of Advanced Passenger Train, in the 1980s.
But financial problems eventually led to the project being scrapped.
When Virgin eventually took over the franchise in 1997, it took another five years before the first train was launched.
Even then it was unable to reach a top speed of 125mph because of delays and overruns on the West Coast line.
Finally the Virgin boss Sir Richard Branson can fulfil one promise he made back in 1997 - a full 125 mph tilting train service from London to Manchester.
He told BBC News 24: "From our original train plan of mission impossible we now have mission completed today.
"Passengers have had to put up with a horrible 30 or 40 years but today is the beginning of a new rail revolution.
"I feel very confident that the main work has been done and Britain can be proud of their railways now and proud of the future".
The tilt allows trains to race through curves at higher speeds.
Work to allow the tilting was essentially finished three months ago, with drivers gaining experience since before full speed was attained.
The Virgin Pendolinos, which are built by Alstom at its Washwood Heath depot near Birmingham, have been used on half of the timetable, but the tilting mechanism was not used.
Plenty of work north of Manchester remains to be done.
It will also be another four years before a notorious bottleneck at Rugby - the cause of many delays - is eased by the construction of two extra tracks.
Pendolinos are much faster than the old stock
But the number of services from London to Manchester is set to double and tilting trains will eventually be introduced along routes to Liverpool and Glasgow.
Caroline Jones, communications manager of the Rail Passengers Committee, added: "I think today is a really positive step forward for passengers.
"The only problem we may have with the new services in the future is the possibility of overcrowding.
"But I think we have to look at this as a step in the right direction and I'm sure we'll see this when the new timetable is introduced next week".