We speak of the age of Euler. A justification of this term is provided by a list of scientific terms connected with Euler’s name and his many contributions to pure mathematics, well-known in the mathematical community and, in part, covered in this volume. What makes this collection remarkable, though, is the extensive treatment of Euler’s contributions outside pure mathematics - astronomy, celestial mechanics, ballistics, music and many other areas. In addition to this survey of his contributions to science, we find also rare, detailed accounts of Euler’s family life and the careers pursued by his children and grandchildren. Readers otherwise well-informed about Euler and his work will find here much to enhance their appreciation of this extraordinary scientist and human being.