The University of Giessen is officially called the Justus Liebig University Giessen (German: Justus Liebig-Universität Gießen) after its most famous faculty member, Justus von Liebig, the founder of modern agricultural chemistry and inventor of artificial fertiliser. The University of Gießen is among the oldest institutions of higher educations in the German-speaking world. It was founded in 1607 as a Lutheran university in the city of Gießen in Hesse-Darmstadt because the all-Hessian Landesuniversität (the nearby University of Marburg (Philipps-Universität Marburg) in Marburg, Hesse-Kassel (or Hesse-Cassel)) had become Reformed (that is, Calvinist). Louis V, Landgrave of Hesse-Darmstadt, whence the university got its original name "Ludoviciana," founded his own institution of higher education in Giessen, which as a Lutheran institution had the primary function of ensuring the education of pastors and civil servants. Endowed with a charter issued by Rudolf II, Holy Roman Emperor, on May 19, 1607, the university was allowed to proceed with instruction in October of 1607.