France's fastest rail link to date has been inaugurated with the service's first train travelling from Paris to the east on Thursday afternoon.
The service will open to passengers on 10 June
The LGV-Est line will now connect the capital with the eastern city of Strasbourg in two hours, 20 minutes instead of four hours previously.
Trains on the line are set to travel at 320km/h (200mph).
The service will open to passengers on 10 June when they will be able to travel further east to other EU states.
Thursday's event was to be marked with a grand light show staged along the 300km (185-mile) railway line.
"Some 37 million Europeans can be reached," TGV-East director Alain Le Guellec said earlier on Thursday.
"A network of high-speed links is being put into place with the rest of Europe."
Train v plane
Mr Le Guellec predicted the "transport revolution" represented by the new line should lead to growth in traffic in the order of 65% by 2011, but he cautioned against predictions of instant success.
Trains on the line will travel at 320km/h (200mph)
"The LGV-Est is an outstanding technical, human and commercial adventure," he said. "But will it be profitable? That's another question."
Air France officials have expressed fears that the new line could have a considerable impact on the one million passengers the airline currently flies to cities in eastern France every year.
It has pledged to reduce fares to counter the competition.
Big project, big numbers
The 4bn-euro (£2.7bn; $5.3bn) project was launched in 2002, with dozens of financial partners - including the governments of France and Luxembourg - sharing the cost.
Hubert du Mesnil, president of RFF, the company that built the line, said the 78,000 metric tons of steel used in the rails is the equivalent of building "eight Eiffel Towers".
He added that 64 million cubic metres of earth had been removed since the start of construction in 2002. That is nine times the volume of material extracted to build the Channel Tunnel, linking France to the UK.
A total of 338 bridges, viaducts and tunnels to allow animals to cross the line had to be constructed, while archaeologists carried out digs along the route at 400 sites, ranging in date from the prehistoric Neanderthal period to World War I.
A second phase of the project is planned, adding a further 100km (62 miles) of track by 2015.
France's TGV trains - launched more than two decades ago - cover a network of 1,500km (930 miles) with an average speed of 300km/h (185mph).