The symposium is organised on the occasion of the research and treatment of the portraits of Marten Soolmans and Oopjen Coppit by Rembrandt van Rijn, jointly acquired by the Rijksmuseum in Amsterdam and the Musée du Louvre in Paris. It will be the first in a series of conferences on the history of conservation. In the future, similar conferences will be organised on the treatment history of paintings by Frans Hals, Johannes Vermeer and Jan Steen.