The exploration of Mesopotamian mathematics took its beginning together with thedecipherment of the cuneiform script around 1850. Until the 1920s, “mathematics in use” (number systems, metrology, tables and some practical calculations of areas) was the object of study – only very few texts dealing with more advanced matters were approached before 1929, and with quite limited results. That this situation changed was due to Otto Neugebauer – but even his first steps in 1927–28 were in the prevailing style of the epoch, so to speak “pre-Neugebauer”. They can be seen, however, to have pushed him toward the three initiatives which opened the “Neugebauer era” in 1929: The launching of Quellen und Studien, the organization of a seminar for the study of Babylonian mathematics, and the start of the work on the Mathematische Keilschrift-Texte. After a couple of years François Thureau-Dangin (since the late 1890s the leading figure in the exploration of basic mathematics) joined in. At first Thureau-Dangin supposed Neugebauer to take care of mathematical substance, and he himself to cover the philology of the matter. Very soon, however, both were engaged in substance as well as philology, working in competitive parallel until both stopped this work in 1937–38. Neugebauer then turned to astronomy, while Thureau-Dangin, apart from continuing with other Assyriological matters, undertook to draw the consequences of what was now known about Babylonian mathematics for the history of mathematics in general.