On May 22, 1453, a partial lunar eclipse (blood moon) occurred during the final siege of Constantinople by Ottoman forces led by Mehmed II, in what is now Istanbul, Turkey. Byzantine defenders and chroniclers viewed the red moon as fulfilling ancient prophecies of the city's doom. The eclipse coincided with the culmination of the Ottoman conquest on May 29, marking the end of the Byzantine Empire and the rise of Ottoman power in Europe and the Middle East.

The event profoundly influenced Renaissance literature and poetry, inspiring laments and epics about the fall of the 'second Rome.' Poets like George of Trebizond and later Western writers incorporated the ominous blood moon into narratives of loss and cultural shift. It fueled millenarian themes in European poetry and contributed to the humanist revival, with echoes in works reflecting on empire, faith, and historical turning points.