The Lettera Matematica PRISTEM is a quarterly journal for mathematical culture which began publication in Italy in 1991 and has been published by Springer since 1997. PRISTEM is the acronym for a historical-mathematical research group based at Milan’s Università Bocconi. The group founded the journal and still directs it. Its editorial board has grown over the years to include mathematicians, historians of mathematics, and scholars from various Italian universities, and recently from some French universities as well.

Each issue of the journal is traditionally divided into four sections: one related to current events and news items from the world of mathematics; one which is largely devoted to increasing awareness of mathematics (divulgation); a third of a historic nature; and a fourth related to problems of teaching and learning mathematics. For some time now, these ‘normal’ issues of the Lettera Matematica have been flanked each year by a special, monographic issue devoted to a special figure or theme in mathematics.

It is precisely here that the journey of the newly founded Lettera Matematica International Edition begins, with a double issue dedicated to Henri Poincaré. This first issue corresponds to issue 84–85 of the Italian edition, which will continue its publication in tamdem with the international edition. The new LMIE is of the same nature as its Italian forerunner: a journal that is sufficiently ‘curious’ about other worlds that come into contact more or less directly with that of mathematics, without being hindered by the disciplinary boundaries that often turn out to be artificial or groundless. Here you will find articles that refer explicitly to mathematical research and its technological applications, as well as others that regard physics and its history, society, educational questions, and scientific policies. These are aimed not only at professional mathematicians, but at teachers, students and those who are not mathematicians but who are, like us, sufficiently curious about the beauty and usefulness of the scientific world. The aim is to arrive at concentric circles that are increasingly large, using simple language—that is, as simple as the complexity of the arguments themselves allows—with the assistance of images where necessary.

These are the hopes of the editors as they inaugurate the Lettera Matematica International Edition. It will then be up to the readers to tell us how close we have come to achieving our aims. We look forward to hearing your suggestions and ideas. Thank you.