The origins of the line design date back to early days of railway building in Italy, some years before the creation of the Italian State in 1859, which explains its tortuous path and its somewhat illogical route in places.

While the Apennines to the north of Florence created a difficult natural barrier, the political frontier with the Papal States to the south also obstructed the development of a rail connection with Rome.

The physical and political geography led to the development of a railway line from the French border, through the Kingdom of Sardinia (Piedmont), Piacenza, and Bologna to Ancona and eventually Brindisi.

The plan for the line between Rome, Orte and Foligno, which is common to the current lines from Rome to the Adriatic port of Ancona and Florence as far as Orte, took shape in the Papal States in 1846 shortly after Pius IX became Pope, replacing his predecessor Gregory XVI who banned railways, calling them "chemins d'enfer" (French for "ways of hell"; a play of words for "chemins de fer", French for "railways").

The company led by Augusto Pietro Adami and Adriano Lemmi, both from Livorno, obtained reconfirmation with a dictatorial decree signed by Garibaldi in Caserta on 25 September 1860.

[4] On 7 July 1861, Act 96 of the Kingdom of Italy gave legislative approval for the concession to the Società delle Ferrovie Livornesi (Livornese Railway Company) to carry out construction work already started[5] for a strada ferrata da Firenze per Arezzo fino all'incontro di quella da Roma ad Ancona ("railway from Florence via Arezzo to that from Rome to Ancona").

While the journey included many curves through beautiful landscape and the ancient towns of Narni, Terni, Spoleto, Assisi and Perugia, in 1871 it meant that a train leaving Florence at 8.05 arrived in Rome at 17.40, that is it took 9 hours 35 minutes to cover 372 km.

[8] The current route connects the stations of Firenze Santa Maria Novella and Roma Termini via Arezzo, Terontola, Chiusi and Orvieto with a total length of 314 km.

The index of tortuosity, according to UIC standards is very high at 68%, which is determined in large part by the presence of five major curves: Fara Sabina, Orte, Ficulle, Arezzo and Pontassieve.