The Klosterneuburg Altarpiece in Verdun is an exceptional work consisting of 45 panels telling stories from the Old and New Testament. One of the panels shows the Queen of Sheba meeting King Solomon and praising his wisdom. She appears here as an elegant and pious figure with black skin but without stereotypically black African physical features. This image illustrates a shift in interpretations of the Queen of Sheba. Where she had previously symbolized pagans who could not understand Christianity, in the German lands she was now being used to represent the pagans who were ripe for conversion. In this capacity she is sometimes depicted as white with an exotic retinue, but she also began to appear as a black figure herself.
As with St. Maurice and the Black Magus, positive depictions of blackness became useful to the Holy Roman Empire for articulating an ideology of Christian or imperial universalism. But while these other figures had a lasting value, a black Queen of Sheba was never accepted uncritically. By the fourteenth and fifteenth centuries her utility had waned. She became an unambiguously negative character, an erotic temptress who led Solomon astray, and her blackness, to the extent it was maintained, was incorporated into newly critical depictions of blacks.
Source: Nicholas of Verdun, Klosterneuburg Altarpiece (1181), Stift Klosterneuburg, Wikimedia Commons.