It was opened in 1927 as a fast link as an alternative to the existing Rome–Naples via Cassino line, significantly reducing journey times.

Partly as a result, it had a tortuous route which, especially in the valley of the Sacco River, was subject to frequent disruption by floods and landslides.

As a result, its route is hilly and in parts mountainous, creating problems for the under-powered steam locomotives of the period.

The project was always controversial: it is supported by railway engineers such as Alfredo Cottrau[4] but opposed by politicians such as Francesco Saverio Nitti.

[5] The final design of the line was drafted in 1902 and approved in 1905 when responsibility for the project was assumed by Ferrovie dello Stato (the State Railways).