When Friedrich Gilly died in 1800 at the age of 28, his architectural career had spanned less than a decade and construction of his major designs was incomplete. Nevertheless, his ideas so strongly influenced Berlin architecture of the next century that he is now widely regarded as the founder of Berlin's distinct architectural tradition. By uniting Rationalist and Neoclassicist principles, his designs achieve an artistic expression that is at once visually dramatic and formally pure. Today, his theories are known primarily through the work of Karl Friedrich Schinkel, his student who became one of Berlin's primary modern architects. In addition to presenting five of Gilly's most influential essays, this volume contains previously unpublished archival records that clarify the intellectual context in which Gilly developed his thoughts on architecture. A catalogue of Gilly's personal library is also presented.