Founded by Duke Rudolph IV in 1365, it is the oldest university in the German-speaking world and among the largest institutions of higher learning in Europe.

However, Pope Urban V did not ratify the deed of foundation that had been sanctioned by Rudolf IV, specifically in relation to the department of theology.

It grew into the biggest university of the Holy Roman Empire, and during the advent of Humanism in the mid-15th century was home to more than 6,000 students.

In addition, epidemics, economic stagnation, and the first Siege of Vienna by Ottoman forces had devastating effects on the city, leading to a sharp decline in enrollment.

Her successor Joseph II continued her reforms and further liberalized the university, abolishing official attire and allowing both Protestants and Jews to enroll by 1782, as well as introducing German as the compulsory language of instruction the year later.

[4] Significant changes were instituted in the wake of the Revolution in 1848, with the Philosophical Faculty being upgraded into equal status as Theology, Law and Medicine.

Led by the reforms of Leopold, Count von Thun und Hohenstein, the university was able to achieve a larger degree of academic freedom.

The previous main building was located close to the Stuben Gate (Stubentor) on Iganz Seipel Square, the current home of the old University Church (Universitätskirche) and the Austrian Academy of Sciences (Österreichische Akademie der Wissenschaften).

On 25 April 1945, however, the constitutional lawyer Ludwig Adamovich senior was elected as the official rector of the University of Vienna.

However, also as part of the 2002 reform, the university, after more than 250 years of being largely under governmental control, finally regained its full legal capacity.

The historical main building on the Ringstraße constitutes the university's center and is commonly referred to as "die Uni".

The Botanical Garden of the University of Vienna is housed in the Third District, as are the Department of Biochemistry and related research centers.

[13] Rudolf IV had already provided for a publica libraria in the Foundation Deed of 12 March 1365, where the valuable books bequeathed by deceased members of the university should be collected.

Through many legacies, this collection was subsequently greatly increased and became the basis of the old Libreye that was accommodated in the same building as the student infirmary.

Today, Vienna's University Library is the largest collection of books in Austria, still facing problems of space.

From 2002 on, the government of Austria, headed by chancellor Wolfgang Schüssel, reformed the university system, transforming the institutions into legal entities, but also concentrating power in the hands of the full professors.

It is rated high in academic reputation and number of international students, but low in terms of faculty-to-student ratio and citations per faculty.

Other famous scholars who have taught at the University of Vienna are: Theodor W. Adorno, Alexander Van der Bellen, Manfred Bietak, Theodor Billroth, Ludwig Boltzmann, Ulrich Brand, Franz Brentano, Anton Bruckner, Rudolf Carnap, Conrad Celtes, Adrian Constantin, Viktor Frankl, Sigmund Freud, Karl Samuel Grünhut, Eduard Hanslick, Edmund Hauler, Jalile Jalil, Leon Kellner, Hans Kelsen, Adam František Kollár, Johann Josef Loschmidt, Franz Miklosich, Oskar Morgenstern, Otto Neurath, Johann Palisa, Pope Pius II, Karl Popper, Elise Richter, Baron Carl von Rokitansky, Rudolf von Scherer, Peter Schuster, August Schleicher, Moritz Schlick, Ludwig Karl Schmarda, Joseph von Sonnenfels, Josef Stefan, Olga Taussky-Todd, Hans Thirring, Walter Thirring, Walter G. Url, Leopold Vietoris, Carl Auer von Welsbach, and Wilhelm Winkler.

Some of the university's better-known students include: Kurt Adler, Franz Alt, Wilhelm Altar, Maria Anwander, Napoleon Baniewicz, Bruno Bettelheim, Rudolf Bing, Lucian Blaga, Hedda Bolgar, Michael Brainin, Josef Breuer, F. F. Bruce, Elias Canetti, Ivan Cankar, Otto Maria Carpeaux, Friedrich Cerha, Felix Ehrenhaft, Olga Ehrenhaft-Steindler, Mihai Eminescu, Stephen Ferguson, Paul Feyerabend, Heinz Fischer, O. W. Fischer, Ivan Franko, Sigmund Freud, Adolf Albrecht Friedländer, Alcide De Gasperi, Hilda Geiringer, Kurt Gödel, Ernst Gombrich, Franz Grillparzer, Karina Grömer, Werner Gruber, Karl Samuel Grünhut, Pamela Gutman, Hans Hahn, Jörg Haider, Friedrich Hayek, Leo-Ferdinand Henckel von Donnersmarck, Theodor Herzl, Anneliese Hitzenberger, Hugo von Hofmannsthal, Edmund Husserl, Marie Jahoda, Max Jammer, Elfriede Jelinek, Percy Julian, Karl Kautsky, Elisabeth Kehrer, Leon Kellner, Hans Kelsen, Hryhoriy Khomyshyn, Jan Kickert, Rudolf Kirchschläger, Arthur Koestler, Jernej Kopitar, Karl Kordesch, Arnold Krammer, Karl Kraus, Bruno Kreisky, Richard Kuhn, Hermann F. Kvergić, Paul Lazarsfeld, Ignacy Łukasiewicz, Gustav Mahler, Tomáš Garrigue Masaryk, Lise Meitner, Gregor Mendel, Karl Menger, Franz Mesmer, Egon Orowan, Franz Miklosich, Alois Mock, Wolf-Dieter Montag, Matija Murko, Paul Niel, Joachim Oppenheim, Eduard Pernkopf, Anton Piëch, Ioan Nicolidi of Pindus, Pope Pius III, Hans Popper, Karl Popper, Otto Preminger, Wilhelm Reich, Peter Safar, Monika Salzer, Mordecai Sandberg, Mordkhe Schaechter, Karl Schenkl, Max Schloessinger, Marianne Schmidl, Andreas Schnider, Arthur Schnitzler, Albin Schram, Joseph Schumpeter, Wolfgang Schüssel, Peter Schuster, John J. Shea, Jr., Mihalj Šilobod Bolšić, Maria Simon, Felix Somary, Marian Smoluchowski, Adalbert Stifter, Countess Stoeffel, Yemima Tchernovitz-Avidar, Eric Voegelin, Kurt Waldheim, Calvin Edouard Ward, Otto Weininger, Slavko Wolf, Eduard Zirm, Stefan Zweig, and Huldrych Zwingli.