Hundreds of Londoners and tourists have inaugurated the first night services of the London Underground on its Central and Victoria lines.
The start of the 24-hour weekend service was scheduled for September 2015 at the hands of then mayor and now foreign minister, Boris Johnson.
However, failures to agree on wage and working conditions for employees resulted in several strikes of network personnel and the postponement of the plan.
Greater police presence was also detected on Tube platforms with 100 additional officers deployed this weekend.
An officer said the force was prepared "to deal with drunk people" but added that so far there had been no such incident.
Even so, alcohol did make an appearance on the morning of the inauguration.
"It is fantastic to have had the chance to take one more drink and not have the metro closed," a happy Adam Smith said.
However, not everyone shared his enthusiasm.
Many taxi drivers in the city have not welcomed the recent development, as a 24-hour Tube service will affect their business.
London Underground - manager of the city's metro network - estimates that 200,000 users will use the night metro every weekend, once all five routes are running.
For London's new Labour mayor Sadiq Khan, who launched the night service, the city's transport is an element of great personal importance.
His father was the driver of the number 44 bus, which is still in operation and links Tooting - the neighbourhood where the mayor was raised - with Victoria station.
- AAP