This book has a long history. It started in 2009, in Budapest, Hungary, when the two authors of this book, Oscar Matsuura and Huib Zuidervaart, met for the first time during the XXIII International Congress of History of Science and Technology. Oscar had already done a lot of research into Marggrafe’s astronomical legacy, both in Paris and Leiden. From the Budapest program, he learned about Huib’s presentation on the use of the telescope in the Dutch Republic, and approached him with the question whether he could tell him something more about Leiden Observatory in the seventeenth century. Huib was very surprised by this question. Why on earth would an astronomer from Brazil be interested in specifically that observatory, at this early period of its existence? Like most Dutch citizens, Huib was then barely aware of the fact that a Dutch colony had once existed in Northern Brazil. Oscar was able to quickly fill that gap in Huib’s knowledge, and concisely told what he knew about GEORG Marggrafe’s pioneering astronomical work in seventeenth-century colonial Dutch Brazil. It was a very inspiring meeting, which led to both researchers joining forces. Oscar’s archival research could be supplemented with some additional research by Huib. This led to joint presentations, first, in September 2010, in Recife, Brazil, during a symposium celebrating ‘GEORG Marcgrave’s fourth centennial’ (see photo), and in October 2012, during the XXXI Symposium of the Scientific Instrument Commission in Rio de Janeiro, Brazil.

In the proceedings of this last symposium a joint paper was published, but long before that the idea had already arisen to extend this piece into a larger biography of GEORG Marggrafe in the English language; this to supplement Oscar’s own book on Marggrafe’s astronomical work, published in the Portuguese language in Recife in 2011.

Busy work on both sides hampered any progress for a long time, which in hindsight was actually a fortunate circumstance, as it allowed the study of a previously unknown second Marggrafe manuscript in Lisbon, as well as a series of Marggrafe draft letters, which in 2017 – by a happy coincidence – were found again in the Leiden City Archives (ELO), after being missing for more than a century.