The Master of Flémalle and Rogier van der Weyden are – besides the van Eyck brothers – of crucial importance for the birth and the beginnings of Early Netherlandish painting. They stand for the discovery of the visible world which they were able to represent in hitherto unknown realistic detail thanks to the sophisticated new technique of oil painting. Though the Master of Flémalle and Rogier van der Weyden number among the most important and innovative fifteenth-century European artists and their opulently detailed narrative paintings belong to the most beautiful and popular works of art from the turn of the late Middle Ages to the early modern age, there has been no monographic exhibition focusing on these two painters and their work to date –irrespective of the fact that the differentiation between the two oeuvres is still controversial. Four monumental monographic books, arriving at partly radically divergent conclusions concerning this issue, have been dedicated to the two artists only in recent years. Under these circumstances, the exhibition organized by the Städel Museum together with the Gemäldegalerie der Staatlichen Museen zu Berlin offers a splendid opportunity to arrive at persuasive answers based on direct comparison in this contentious matter. Both the Städel Museum in Frankfurt and the Gemäldegalerie der Staatlichen Museen zu Berlin boast incomparable holdings as regards the Master of Flémalle and Rogier van der Weyden, which will be brought together in this exhibition for the first time. More than 50 masterpieces by the two artists – nearly all surviving and transportable paintings – will be assembled for the occasion. Many of the works have never been lent out before, most of the works will be presented together for the first time. The show thus provides a unique occasion to experience the visual world of two of the most important and influential fifteenth-century artists in a hitherto unknown quality and density. The question, however, is the identity of the Master of Flémalle. This exhibition might contribute to the solution of the puzzle.