Bladelin Altarpiece

The stable is a half-ruined thatched Romanesque building, rather than the traditional wooden hut, with stone walls and arched windows, and one prominent classical pillar, uniquely in van der Weyden's work shown in an oblique perspective view.

The left panel draws from the Speculum Humanae Salvationis and depicts the legendary occasion when the Roman Emperor Augustus consulted the Tiburtine Sibyl to ask if he was the greatest man on earth and if he should consent to being worshiped as a god; the Sybil revealed to him a vision of the Virgin and Child, and Augustus then reputedly founded an altar in Rome to the "firstborn of god" (Ara primogeniti Dei) at the location now occupied by the Ara Coeli.

The emperor is kneeling next to the Sybil, looking towards the central panel to observe the vision through a window symbolically marked with the double-headed eagle of the Habsburgs; to his right stand three attendants, possible based on courtiers of the Philip the Good; all are wearing 15th century Flemish dress.

The side panels of the altarpiece would only be opened to reveal the brightly coloured images inside for church services at the weekend and on other special occasions.

The work may have been donated by Pieter Bladelin (c. 1410-72), treasurer of Philip the Good, Duke of Burgundy, as the altarpiece for the new town church of Saints Peter and Paul in Middelburg in Flanders.