The Hanoverian state minister and first university curator Gerlach Adolph von Münchhausen (1688-1770) proved to be an effective supporter of the library. These favourable conditions allowed the library directors Johann Matthias Gesner (1734-1761) and Christian Gottlob Heyne (1763-1812) to assemble holdings of unprecedented completeness and range. Heyne was in charge of the library for almost 50 years and developed it to a model research library. As he wrote in 1810, he understood the significance of acquisition as follows:
"[C]ontinuous systematic acquisition of what is needed [...] for a library which is organised according to a scientific design, not according to predilection for a particular subject, not for ostentation, not for the lustre of outer appearance, but as a compendium encompassing the most important writings of all periods and peoples in all sciences."
The library holdings should document the progress of scientific research instead of recapitulating familiar facts.
Within just a few decades, Heyne created a dense network of contacts with foreign book dealers, diplomats and scholars to acquire literature from all over the world. Due to the personal union between Hanover and Great Britain which lasted until 1837 the book collection showed an emphasis on Anglo-American cultures; and as the University of Göttingen held close ties with Russia, the Slavic cultures formed a second focus. This profile was complemented by the natural sciences.
A number of catalogues indexed the holdings in an exemplary way. In addition to the shelf-register for the Bülow Collection, which was continued as an accession catalogue, an alphabetical catalogue was introduced in 1743, and a classified one in 1755. These retrieval aids were interlinked and formed the Göttingen Catalogue System.
The University Library was characterized by a liberal usage policy and soon allowed students to borrow books, which was not common at the time. This way, within a few decades the University Library Göttingen became the first modern universal library of European renown. Around 1800 it already comprised about 150,000 books. During the time of Heyne’s directorate the holdings had tripled.