The altarpiece 's date is uncertain but believed to be between 1435 and 1438 . Van der Weyden was made painter to the city of Brussels in 1435 , and it is believed to have been painted after this appointment . The National Gallery give " before 1438 " . Art historian John Ward note that the altarpiece was one of van der Weyden 's first masterpieces , created early in his career when he was still heavily influenced by Robert Campin . He propose a c . 1437 date based on similarities to Campin 's Werl Altarpiece .