At the time the university was founded, it was immediately determined that a library in the vicinity of lecture halls was an absolute necessity. The library's first book was the Polyglot Bible, printed by Christoffel Plantijn, a gift of William of Orange to the library in 1575. The presentation of this book is regarded as the base on which the library is built ("fundamentum locans futurae aliquando bibliothecae"). The library became operational in the vault of the current Academy building at Rapenburg on 31 October 1587.