The 'Connecting Europe Express' has left Lisbon station on a five week journey that will stop in more than 100 towns and cities.
This special train is aimed at highlighting the challenges preventing rail from being a more popular travel choice for Europeans.
It will take in 26 countries and clock up a distance of 20,000 kilometres, finishing in Paris on October 7.
The Connecting Europe Express initiative is the European Commission's flagship project for promoting the benefits of rail travel and raising awareness of the challenges that still need to be overcome.
"Rail has shaped our rich, common history. But, rail is also Europe's future, our route to mitigating climate change and powering economic recovery from the pandemic, as we build a carbon-neutral transport sector, " says European Commissioner for Transport Adina Vălean.
"Over the coming weeks, the Connecting Europe Express will become a rolling conference, laboratory and forum for public debate on how to make rail the transport mode of choice for passengers and businesses alike."