It used to be three. Or eight, in fact.

The classical high school (liceo classico) finds its roots in the "ginnasio-liceo" established in 1859 by the Casati law, as a school following elementary school (made compulsory), initially in force only in the Kingdom of Sardinia and then extended to all of Italy after the unification. High schools already existed, having been established in the Napoleonic era, to ensure high-level education even by secular institutions. With the Casati law, as in the rest of Europe, they wanted to put order in the sector, specifying what were the prerogatives of the state in terms of education.

On the model of the pre-unification humanistic scholastic tradition, the Casati law provided for a single high school address in which literary and humanistic subjects were prevalent. The original study plan provided for an eight-year course (since there was no middle school at the time), divided into five years of high school (ginnasio) and a three-year high school: the study of Latin began in the first secondary school, that of Greek in the third.

The high school gymnasium was an eight-year secondary school. It was accessed after elementary school (initially for four years) and gave access to any university; the high school gymnasium was the only secondary school-type course, that is, not aimed at technical-professional training, but at the continuation of studies at the university.

The high school gymnasium outlined by the Casati law remained substantially unchanged until 1923, even if the programs and schedules were renewed several times (in 1867, 1884, 1888, 1892). The timetable of 1892 introduced the study of French from the third gymnasium to the fifth gymnasium, filling the lack of a foreign language.

At the beginning of the twentieth century, having emerged the problem of the lack of mathematical / scientific education, individual high schools were allowed to activate experimental sections in which, instead of Greek, mathematics or a modern language could be taught. In 1911 the modern high school was established, which joined the traditional course; to distinguish it from the latter, the traditional high school gymnasium began to be informally called "liceo classico", even if, officially, the name remained "liceo ginnasio".

The modern high school was abolished in 1923 with the Gentile reform, which at the same time established the liceo scientifico (scientific high school).

In Gentile's idea, the elite school had to coincide with the "classical" high school, intended for the training of the future ruling classes and for this place in a privileged position vis-à-vis the other upper secondary courses: only graduates with a classical high school diploma were granted free enrollment in any university faculty, while for example those who came from the scientific high school could not enroll either in literary studies or in law school. This latest foreclosure was particularly serious, as this was the preferred degree for politicians and parliamentarians.

The profound changes made to the entire school system will also affect the classical high school: the new five-year state elementary school guaranteed adequate preparation but to access the gymnasium it was necessary to pass a new demanding admission exam; equally demanding exams were foreseen between the third and fourth year of secondary school, between the fifth year of secondary school and the first high school year and, at the end of the course, the new maturity exam, an extremely rigorous state exam. The new ministerial programs exalted the aesthetic-literary component: the study of Italian and philosophy was structured historically as a study of the history of literature and philosophical thought. The official name remained "high school gymnasium", although the last three years was currently called "classical high school", to be able to distinguish it from scientific high school.

In 1940 Bottai established the "unified" three-year middle school, which absorbed the first three years of high school: since then the classical high school is structured as a five-year school, but kept the numbering of the previous classes (therefore the first two years are the fourth and fifth years of the ginnasio, the last three are the first, second and third years of the high school: the numbering is peculiar, since the other secondary schools provide classes from the first to the fifth corresponding to the years.

Apart from some necessary adjustments to the timetables, such as the division of history and geography into two individual subjects for the fourth and fifth year of secondary school, the new course remained substantially identical to the previous one.

On this occasion the official name was changed to "liceo classico", classical high school"; the denomination of the years of the course, however, remained the traditional one, still in force: after the 3rd grade there are the 4th and 5th secondary schools and then the 1st, 2nd and 3rd High schools.

In 1969, access to the university was liberalized, putting an end to the pre-eminence of the classical high school over other secondary studies: enrollment in each faculty was granted to all graduates of secondary education institutions of second degree of duration. five years (technical high schools included). At the end there are five high school courses (classical, scientific, linguistical, human sciences and artistic) plus technical three-, four- and five-year technical schools.