It is well known that the royal power has always built castles, fortifications, entire cities and other architecture to consolidate its power. Individual royalty’s interest in architecture and, in some cases, practicing as architects, has, however, been less researched. Recently, research on King Gustav III of Sweden (1746-1792) has shown that he himself was the architect behind several important building projects. Even his relative George III of England (1760-1820) had a deep interest in architecture and drawings and sketches by his hand are preserved. In this book, several researchers contribute additional examples and perspectives on the importance of royalty for architecture, on both a personal and political level.