Buildings and the Geometry of Diagrams : Lectures given at the 3rd 1984 Session of the Centro Internazionale Matematico Estivo (C.I.M.E.) held at Como Italy August 26–September 4 1984 The geometry of the finite simple groups Generalized polygons SCABs and GABs Immeubles de Type Affine Point line characterizations of buildings Constructions of chamber systems of type M with transitive automorphism group Covers of finite geometries with non spherical minimal circuit diagram A construction of buildings with no rank 3 residues of spherical type Tits chamber systems and finite group theory.