During the first half of the 18th century, under two rulers, Augustus the Strong (ruled 1694-1733) and his son, Augustus II (ruled 1733-1763), Dresden became a major European cultural center. The Court Library became a true state library for Saxony, absorbing many manuscripts, maps, and books from distinguished private collections, with some spectacular purchases, such as the Dresden Codex that was obtained in 1739. In 1727, the library moved into two wings of the Zwinger Palace. When Frederick the Great of Prussia attacked Dresden in 1760, part of the library burned; there are singed volumes in the collection to this day. By the end of the 18th century it had outgrown its wing of the Zwinger, and the library then moved to the Japanese Palace. In 1788 the Saxon Library was opened to the public. Following the proclamation of the Weimar Republic in 1919, it officially became the Saxon State Library, with its strengths continuing to lie in the arts, humanities, social sciences, literature and linguistics.