Founded in the second half of the 17th century, the University of Zagreb is the oldest university with continuous activity in Croatia and among the oldest in Europe. The Charter of King Leopold I of 23 September 1669, the Jesuit High School in Zagreb granted it the status and privileges of a university institution – a three-year higher education study programme was approved from which over time studies of philosophy, law, and theology developed. Following a decision of the Croatian Parliament and confirmation by King Franz Joseph I, the Act on the Establishment of the University of Zagreb entered into force on 5 January 1874. At the opening ceremony of the University on 19 October 1874, Ban Ivan Mažuranić appointed Dr Matija Mesić as rector, who then began implementing his famous and visionary programme, which still bears significance to this day. This date was the beginning of organised scientific and teaching work at the University of Zagreb. The Law, Wisdom (later Philosophy), and Theology faculties were founded.
The subdepartments of the Department of Natural Sciences and Mathematics began to function gradually, after the appointment of certain professors. Not two years after the University was established, Professor Gjuro Pilar began teaching at the Department of Natural Sciences and Mathematics of the Faculty of Philosophy on 21 April 1876, which is why this date is when each year we celebrate the Faculty of Science Day. Alongside Gjuro Pilar, Dr Bohuslav Jiruš, professor of botany, and Dr Vinko Dvorak, professor of physics, start holding classes. Mathematics classes (Dr Karel Zahardnik) and chemistry classes (Dr Aleksandar Velkov) began in 1876, while topology started in 1877. Today’s Faculty of Science was founded by a decree of the Government of the People's Republic of Croatia on 8 June 1946 separating subdepartments from the Faculty of Philosophy. This event also marked the beginning of the development of all traditional and the introduction of new natural science and mathematics disciplines at the University of Zagreb.
The Faculty statutes of 1956, 1959, 1964, and 1967 advanced the curriculum and mode of study in particular. The honour of being the first dean of the Faculty of Science was bestowed upon academician Fran Tućan (1878-1954), a prominent populariser of science, president of Matica Hrvatska, and editor of the journal Priroda. Slowly, with broader reform efforts, the quality of scientific and teaching activities was raised. In 1948/1949, classes according to annual study programmes began taking place. In 1962, a qualification (entrance) exam for high school students was introduced, and in the same year the title of graduate engineer was introduced for all those graduating from the professional programme. Now, 73 years after its establishment, owing to the number of students and staff, the Faculty of Science is not only among the largest constituents of the University of Zagreb, but also a scientific and educational environment that acts as one of the most important educators of scientific personnel in Croatian natural sciences and mathematics and secondary school teachers as well as a leading centre of research within these scientific fields.