Physics was transformed between 1890 and 1930, and this volume provides a detailed history of the era and emphasizes the key role of geometrical ideas. The first part of the book discusses the application of n-dimensional differential geometry to mechanics and theoretical physics, the philosophical questions on the reality of geometry, and reviews the broad international debate about the nature of geometry and its connections with psychology. The second part then examines the reception of Einstein's theory of special relativity following 1905. It covers Minkowski's reformulation of the theory, providing the first complete picture of his work, and it describes Einstein's path to formulating general relativity. The chapter on Hilbert's efforts to axiomatize relativity argues against the traditional view of Hilbert as arch-formalist, and the following chapter provides the first detailed account of Emmy Noether's work on physics. The final section examines the work by Ricci, Levi-Civita, and Weyl to give a new formulation of general relativity in terms of the Riemann differential. This collection will be an invaluable resource for historians and philosophers of science.