After the reforms of Peter the Great, Russia's architecture became influenced by Western European styles. The 18th-century taste for Rococo architecture led to the splendid works of Bartolomeo Rastrelli and his followers. During the reign of Catherine the Great, Saint Petersburg was transformed into an outdoor museum of Neoclassical architecture. During Alexander I's rule, Empire style became the ''de facto'' architectural style, and Nicholas I opened the gate of Eclecticism to Russia. The second half of the 19th-century was dominated by the Neo-Byzantine and Russian Revival style. In early 20th-century, Russian neoclassical revival became a trend. Prevalent styles of the late 20th-century were the Art Nouveau, Constructivism, and Socialist Classicism.