Preface.- Part I Mathematical and Physical Underpinnings of Spacetimes.- Figures of Light in the Early History of Relativity (1905-1914).- The Behaviour of Rods and Clocks in General Relativity and the Meaning of the Metric Field.- Hilbert on General Covariance and Causality.- Part II Testing General Relativity and Rival Theories.- Putting General Relativity to the Test: Twentieth Century Highlights and Twenty-First Century Prospects.- Rotating Hollow and Full Spheres: Einsein, Thirring, Lense, and Beyond.- Relativistic Lighthouses: The Role of the Binary Pulsar in Proving the Existence of Gravitational Waves.- The Rise and Fall of the Fifth Force.- Part III Geometry and Cosmology, Past and Present.- Cyclic Models of the Relativistic Universe: The Early History.- Inflation and the Origins of Structure.- Problems with Modified Theories of Gravity, as Alternatives to Dark Energy.- The Unexpected Resurgence of Weyl Geometry in Late 20th-Century Physics.- Part IV Mathematical Motifs in General Relativity and Beyond.- Matter from Space.- The Surprising Resolution of the Poincarén Conjecture.- Unified Field Theory up to the 1960s: Its Development and Some Interactions Among Research Groups.- Part V Quantum Gravity, Conformal Boundaries, and String Theory.- The Formulation of Quantum Field Theory in Curved Spacetime.- Conformal Infinity - Development and Applications.- String Theory and Spacetime Geometry.- Conference Program.
