The University and State Library is closely linked to the history of the castle in Darmstadt. The first evidence of a court library dates back into the 14th century. Starting with the private book collection of Count George I which was brought to Darmstadt at his accession in 1567, the stocks grew over the years by targeted purchases and acquisitions of private and monasterical collections. A main role in this development played Count Ludwig, the later Grand Duke Ludewig I. In the 17th century the library was situated in the clock tower, only in the 19th century it moved into the South-East wing of the baroque castle built by the French architect Louis Remy de la Fosse. In 1817 the Grand Dukal Library opened for the public for the first time, five days a week. At the beginning of the 20th century the library with 450,000 books was counted among the biggest libraries in the German Reich. In 1920 it was officially named „Hessian State Library“ and in 1932 it was enlarged again into the South-West wing of the castle due to lack of space.
The State Library as well as the Library of the Technical University founded in 1872 lost more than half of their stacks in the socalled „Night of Fire“ in 1944. The castle of Darmstadt was destroyed down to its foundation walls by allied bombing. But as early as in 1945 the State Library opened again in the vaults of the West wing, merged with the Library of the Technical University in 1948 and from then on was named „Hessian State and University Library Darmstadt“. As late as in 2000 the library was also administratively attatched to the Technical University and is called „University and State Library Darmstadt (ULB)“ since 2004.
The relocation of the Hessian State Archive in the 1990ies allowed a further enlargement in the South-East wing of the castle. However, the constant space contraints, the aging building structure, the desolate fire protection, and the assimilation of departmental libraries required two new buildings in the municipal centre and on campus Lichtwiese which opened in 2012 and 2013. So for the first time in more than 440 years the castle did not host a library any more. Therefore, the relocation of selected book stocks into the castle now continues again a long and succesful tradition.