This chronology is from a Guardian interview with George Dyson, who's just written Turing's Cathedral: The Origins of the Digital Universe. One of the central features of the book is to restore prominence to John von Neumann, the great Hungarian polymath.
1936 Alan Turing submits his paper 'On computable numbers, with an application to the Entscheidungs problem' to the Proceedings of the London Mathematical Society.
1941 Konrad Zuse working in isolation in Germany, builds the Z3. He knows nothing about Turing's work.
1944 The first Colossus computer is operational at Bletchley Park, Buckinghamshire, significantly contributing to the allied war effort by doubling the codebreakers' output. It contained 1,500 thermionic valves, was the size of a room and weighed around a ton. In all, 10 Colossus computers were in use by the end of the war.
1945 John von Neumann publishes a paper setting out the architecture of a stored-program computer.
1946 First public showing of the Eniac computer built in the preceding three years at the University of Pennsylvania.
1952 Von Neumann's IAS computer becomes operational and is extensively cloned – there is no patent.