The painting Rüstem Pasha Mosque Istanbul by Jean-Léon Gérôme (1824–1904) depicts a group of men in a mosque, gathered in a semicircle in front of the mihrab and shown in various states of prayer. The richly decorated interior demonstrates Gérôme’s dedication to architectural accuracy: the French artist reproduced objects from Islamic material culture, such as the two monumental candlesticks, the blue and white Iznik tiles, and an Arabic inscription on the walls of the mosque, in a precise manner. In the upper right part of the painting, he depicted a colourful stucco and glass window with the motif of stylized flowers symmetrically disposed in a vase. The light-flooded window is partially covered by the minbar (pulpit) and two green flags attached to it.

In 1875, the French painter Jean-Léon Gérôme (1824–1904) travelled to Istanbul for the third time, and made about fifteen studies of mosques, including the Rüstem Pasha Mosque (Roberts, 2010, pp. 120–122). An undated oil study by Gérôme, showing the qibla wall of the mosque, built by Mimar Sinan in 969 AH / 1561 CE, is probably one of these works (now in the Musée Georges Garret in Vesoul, IG_434). In this study, the stucco and glass window on the right side of the mihrab consists of large blank glass panels in curvaceous shapes, a type of stucco and glass window that appeared in the 18th century in Istanbul and its nearby provinces (see Bakirer, 1985, p. 152; Bakirer, 2001, p. 12).
In the oil painting discussed here however, Gérôme did not represent the actual geometric window of the mosque, but depicted rather a stucco and glass window with the motif of a vase with symmetrically disposed stylized flowers. It is a copy of a window in a chromolithograph by the French Orientalist Émile Prisse d’Avennes (1807–1879) that was reproduced in his L’Art arabe d’après les monuments du Kaire, published in four volumes between 1869 and 1877 (IG_31). It shows the upper room of the Cairene house of ‘Sidi Youçouf Adami’. Prisse d’Avenne’s publication became one of the most important reference works for European Orientalist painters in the second half of the 19th century. But, in Gérôme’s case, the transfer may not have happened through the book, but directly through an actor: it was the Dutch painter Willem de Famars Testas (1834–1896) who in 1858 had made the preparatory drawing(s) for Prisse d’Avenne’s lithograph of the ‘Maison Sidi Youçouf Adami’, and de Famars Testas was also well acquainted with Gérôme, as he had accompanied him on his trip to Egypt in 1868 (de Hond, 2013, p. 92, n. 3).
In his oil painting, Gérôme transferred the stucco and glass window of a domestic house in Cairo to a religious building in Istanbul, relocating it to a new geographical and architectural context. Gérôme combined two sources – Prisse d’Avennes’s book illustration, and his own studies made on site – to create his painting and to provide a supposedly authentic image of a religious interior in the Ottoman empire.