Information about the origin and history of the painting, the Wedding of Peleus and Thetis, painted by Cornelis Cornelisz. van Haarlem in 1593, proved helpful in understanding its present condition. This information was gained by comparing results of archival research with those obtained by technical examination of the painting. The examination on the object itself was very remarkable. Due to the fact that a controversy surrounded the last restoration of the painting in 1875, ideas concerning how the treatment should be carried out have been recorded. While the early conservative treatment recommendations agree with current approaches to restoration, this does not seem to have been the practical result. Such investigations allow us to trace the profession of the restorer in the past. -- CAL