A new 24-hour Tube service at weekends will begin in the early hours of September 12 next year, it was announced today.
Transport for London (TfL) said the new service had been made possible thanks to the continued modernisation of significant parts of the London Underground (LU) network and improved levels of reliability.
It was first promised by mayor of London Boris Johnson and LU last November.
TfL said the launch of the "Night Tube" would coincide with the start of the Rugby World Cup, which is hosted in England between September 18 and October 31 next year.
The tournament will be hosted in 13 venues around the country, including three in London - Twickenham Stadium, Olympic Stadium and Wembley Stadium - and the new service will provide fans attending these matches, and the expected 400,000 overseas visitors into England, with additional transport options.
The service is expected to reduce night time journeys by an average of 20 minutes, with some cut by more than an hour. It will also support London's businesses, jobs and leisure opportunities.
In order to meet expected demand, there will be six trains per hour through central London on all Night Tube lines, including the Jubilee, Victoria and most of the Piccadilly, Central and Northern lines. On the Northern line, there will be eight trains per hour to meet demand at busy stations between Leicester Square and Camden Town.
Mr Johnson said: "London is a bustling, 24-hour global city and by this time next year we'll have a 24-hour Tube service to match. Running trains all through the night was once thought impossible, but with the huge investment we've put in and upgrades that have been delivered we stand ready to take the Tube to the next level.
"As well as creating vital new jobs and giving a huge boost to our economy, the Night Tube will help millions of people to get around our city more easily and quickly. The evolution of the Night Tube will without doubt make London an even better place to live, work, visit and invest."
Mike Brown, managing director of LU, said: "We are now less than a year away from the first ever 24-hour services operating on London Underground. Already over half a million Londoners use the Tube after 10pm on Fridays and Saturdays, and the introduction of the Night Tube, which will cut journey times and open up new possibilities across the night time economy, is a historic step in our modernisation of the Underground.
"The new service will boost jobs and will benefit the economy by hundreds of millions of pounds. We will also now be exploring any sponsorship opportunities that could make this transformative service even more cost-effective."
Manuel Cortes, leader of the TSSA rail union, said: "We welcome the 24-hour Tube but we want talks with management to ensure it is not going to be a low cost, low maintenance weekend service.
"With Boris still wanting to axe 900 jobs and close all ticket offices, we want to ensure that the new service is properly staffed to ensure safe and secure travel for all passengers and that weekend maintenance work is not postponed to disrupt weekday services."
Mick Cash, Rail, Maritime and Transport union general secretary, said: "Whilst RMT is not against night running of the tube, provided all staff involved are properly rewarded and that safety and security is thoroughly worked out and agreed, the truth is that the Mayor threw this plan in as a diversion from his massive cuts and closures programme that will axe a thousand staff and decimate services and safety.
"Instead, this proposal is now being bulldozed through without any proper risk assessment or agreement on core issues. To make this plan work we need more Tube staff not less if we are not going to be risking disaster at 3am when the West End is flooded with thousands of people fresh out of the pubs and clubs."