Since 1634, the Augustinerkirche has been the historic parish church of the Hofburg, the winter palace of the Habsburg dynasty in the center of Vienna. In 1327 duke Frederick the Handsome (Friedrich der Schöne) founded this church with a cloister for the Augustine monks. It is thus always called The Augustinian's Church by the Viennese, although its official name is St. Augustin's Church.
The nave was built under architect Dietrich Landtner from 1330 to 1339, but not consecrated until 1 November 1349. As the nearby Hofburg expended, the Augustinerkirche gradually became engulfed by it and today is a part of the complex. Although inconspicuous from the outside, the inside is more ornate. During the reign of Emperor Joseph II, 18 side altars were removed in 1784 when the church was restored in the gothic style. A new side altar was added in 2004, dedicated to Emperor Karl I of Austria (1887 - 1922) who is on the path to being recognized as a saint by the Roman Catholic Church.
As the parish church for the imperial court, it was the scene of many Habsburg weddings, among them Archduchess (and future Empress) Maria Theresa in 1736 to Duke Francis of Lorraine, Archduchess Marie Louise in 1810 to Emperor Napoleon Bonaparte of France, and Emperor Franz Joseph in 1854 to Duchess Elisabeth of Bavaria. Notable among the church's monuments are the memorial to Marie Christine of Austria sculpted by Antonio Canova, and the Herzgruft containing the hearts of 54 members of the imperial family. A functioning monastery of six black-robed Augustinian monks remains, serving the needs of the pari.

Text Source: Wikipedia