Since 1571 the Jesuits had been pushing the re-catholization in the predominantly Protestant city of Graz according to the wishes of the Archduke Charles II of Austria.
It grew rapidly because many books got transferred from monasteries to Graz and because of donations and continuous purchases.
Natural sciences were well represented due to the influence of the mathematician Paul Guldin, who was one of the university professors.
The 28 volume library catalogue was untraceable, it might have been taken away or destroyed by some glowering Jesuits and has never been detected until today.
Only when the number of personnel was raised from 3 to 6 and the endowment from 830 to 4000 guilder in 1870, the university could again accomplish its tasks properly.
Due to the limited space at the city centre, a new complex of buildings was erected in the periphery (present day Geidorf) in 1891.
At the same time another building was erected directly attached to the library's original front leaving it unaltered.
Together with the University Libraries of Vienna and Innsbruck Graz has been assuming control of the establishment of national and international consortia installed in order to use electronic journals and books in cooperation and thus more cost-effectively in 1998.
At the turn of the millennium, the actual stocks were almost 3 million printed books, more than 2000 manuscripts, about 1200 incunabula, bequests of many scholars and about 1400 current periodicals.
Some of the most notable parchment manuscripts are the five oldest Georgian scripts (7th to 11th century) found in the Saint Catherine's Monastery at the foot of Mount Sinai.
In 2023, Theresa Zamit Lupi discovered a thread in one of 42 papyrus-manuscripts from Oxyrhynchos dating from 260 BC, which is an indication of a binding in codex form.