Marchesi. Court Library Originally a free-standing structure, the Court Library (Hofbibliothek) was housed on the other side of the complex. Charles VI had the main building and the Prunksaal main hall constructed. Today it is under the auspices of the Austrian National Library. Its construction was begun by Johann Bernhard Fischer von Erlach and finished by his son Joseph Emanuel in 1735. The large Prunksaal hall contains the book collection of Prince Eugene of Savoy, an enormous ceiling fresco by Daniel Gran, and statues of emperors by Paul Strudel making this part of the Hofburg its most significant in artistic terms. The exterior decoration with attic style figures was executed by Lorenzo Mattielli in 1726. He placed a statue of Athena riding on a quadriga above the main entrance. On the left portion of the roof, he situated Atlas, supporting the celestial globe, flanked by Astronomy and Astrology, and on the opposite side, Gaia with the terrestrial globe, flanked by allegories of Geometry and Geography. The library to the north is located at Joseph Square. More structures and annexes were successively added. Particularly from 1763 to 1769, Nicolo Pacassi connected the Imperial Library to the other parts of the Hofburg and its other side to the Augustinian Church and he thus created the present Joseph Square (Josephsplatz), marked by its almost symmetrical proportions. Joseph Square Of note are the bronze equestrian statue of Emperor Joseph II. Augustinian Wing Built right before the adjacent Court Library, on the south-east side of Joseph Square, lies the baroque Augustinian Wing with the Augustinian church and monastery. As the palace expanded, the church and monastery became an integral part of the building. The Augustinian Church was used by the Habsburgs as their court church and also for weddings. This is where Emperor Franz Joseph I and Empress Elisabeth, alias Sisi, were married. Behind the Loreto side chapel is located the Hearts' Crypt, a semicircular-shaped annexe separated by an iron door, where 54 hearts of House of Habsburg members are kept in silver urns. The Palais Archduke Albrecht (formerly Palais Tarouca-de Sylva), home of the Albertina museum, is also considered a part of the Hofburg because of its structural connections to the Augustinian monastery. In the early 19th century members of the imperial family had their residence here, such as Archduke Albrecht and, later, his nephew, Archduke Friedrich, Duke of Teschen. After the renovation of