text: Frederick had many famous buildings constructed in his capital, Berlin, most of which still stand today, such as the Berlin State Opera, the Royal Library (today the State Library Berlin), St. Hedwig's Cathedral, and Prince Henry's Palace (now the site of Humboldt University). A number of the buildings, including the Berlin State Opera House, a wing of Schloss Charlottenburg, and the renovation of Rheinsburg during Frederick's residence were built in a unique Rococo style that Frederick developed in collaboration with Georg Wenzeslaus von Knobelsdorff. This style became known as Frederician Rococo and is epitomised by Frederick's summer palace, Sanssouci (French for "carefree" or "without worry"), his primary residence and private refuge.
  As a great patron of the arts, Frederick was a collector of paintings and ancient sculptures; his favourite artist was Jean-Antoine Watteau. His sense of aesthetics can be seen in the picture gallery at Sanssouci, which presents architecture, painting, sculpture and the decorative arts as a unified whole. The gilded stucco decorations of the ceilings were created by Johann Michael Merck and Carl Joseph Sartori. 17th-century Flemish and Dutch paintings filled the western wing and the gallery's central building, while Italian paintings from the High Renaissance and Baroque were exhibited in the eastern wing. Sculptures were arranged symmetrically or in rows in relation to the architecture.
  Science and the Berlin Academy