The two innocent sleeping children seen here are thought to be Clara and Philip, the children of Rubens's elder brother. This elder brother, Philip, was extremely close to Rubens and he died in 1611. He left two children, born in 1610 and 1611, and Rubens is thought to have created this study from his deep regard for his brother. Judging from the ages of the children, this work is thought to have been painted around 1612/1613. Rubens later used the faces of these two children in large-scale paintings in oils, respectively the Madonna in Floral Wreath (Alte Pinakothek, Munich) and the Madonna and the Angels (Musée du Louvre, Paris). This work is a study work, revealing the freshness found in sketching directly from a subject, and yet it is a superb example of the artist's inimitable brush, particularly in the truly touchable depiction of the rich fleshiness of the children's cheeks. This is an example of Rubens's uncanny ability to evoke an image of his subject through an adroit use of transparent pigments and opaque pigments, adjustments of light and dark tonalities and differences in the thickness of paint application. Radiographic examination reveals that originally the child on the left was awake and looking straight ahead. (Source: Masterpieces of the National Museum of Western Art, Tokyo, 2009, cat. no. 26)