The 500th anniversary of Regiomontanus's birth has occasioned this depiction of his life and work. It is the first English translation of Ernst Zinner's monumental biography, plus a number of specially-written supplementary articles which help paint a more comprehensive picture of the current state of knowledge about Regiomontanus. The articles show the high regard in which the biography is still held by the community of scholars doing work on the mathematics of the Renaissance.Zinner's biography is a mine of information about early printing, astrolabes, tables of eclipses and the world of Henry of Langenstein, Johann of Gmunden, Georg Peuerbach, Cardinal Bessarion, Nicholas of Cusa and the extraordinary itinerant scholar, Johannes Müller of Königsberg — Regiomontanus. His contributions to mathematics are discussed (for example, he may have discovered the fifth and sixth perfect numbers) as well as the mysteries surrounding his life and death.