German architect, part of a Bavarian family of architect, son of Christoph Dientzenhofer. He was one of the most important representatives of the Baroque style in Bohemia and continued in the footsteps of his father. He studied in Prague and Vienna, travelled to Paris and Italy and settled in Prague in 1715. He mainly worked for church orders, to lesser extent for nobility. He created an original style based on penetrating oval spaces, but later on he made the buildings simpler and he conformed to the Classicist trend; at the end of his creative life he succumbed to the Rococo style. Among his individual works are the church of St. Thomas (1725-31; a Gothic structure reworked into Baroque) and the church of St. John on the Rock (1730-39; including the Vyšehrad Steps), both of which are in Prague, as well as the church of St. Mary Magdalene, Karlsbad (now Karlovy Vary; 1733-36). He also built the Villa Amerika (1712-20; afterward the Antonin Dvoøák Museum), Prague. From 1737 he was the chief fortress builder in Bohemia. //