from Barcelona to Rome by train

You can check the german rail site for specific schedules, but it should take about a full day and overnight's worth of travel. In other words, it's a very long trip. To fly would be a few hours and cheap flights are pretty easy to find now.

It is a long trip by train. Flying would be much easier.

Your best train route is the EN night train from Barcelona Franca to Torino and a EuroStar Italia train from there to Roma Tiburtina. Depart at 19:25 and arrive at 13:25. Your budget airline choices are Barcelona-Ciampino on Ryanair and Barcelona-Fiumicino on Vueling. Ryanair can have cheaper fares, but Ciampino is an outlying airport.

Phyllis As the other posters have said, flying costs less in time and money. Go to Skyscanner.com for discount airline routes and prices. Just be sure to read the FINE PRINT. Luggage restrictions are strict on size, weight, etc and overages can cost you more than the flight! You also pay for everything, seat assignments, early boarding, drink, food, etc. Still very worthwhile and cheap! Make sure you go all the way to the end for the total price as the opening price is just a teaser. Bobbie

Keep in mind you won't always need all the extras, the flight isn't more then 1.5 -2 hours,, so imagine most of us can go without food,, or bring a snack onboard( its allowed) and seat assignments and express boarding all truly extras. I just got a ticket from Barcelona to Paris on Vueling, and after going on several forums basically decided the advance boarding fee was not needed,, everyone said they manage to get a seat near their travelling companions as it was, and that unless you are travelling with children there was not point in paying extra for seats or pre boarding. I do however recommend paying for the checked bag ahead of time,, if you "hope" your luggage is carryon size and get to airport and they decide its not,, the fee for checking the bag then is much higher. I have used Vueling before and thought they were absolutely fine.