This paper considers the role of visual sources in public debates about the English Reformation. It focusses on a case study – The Lambe Speaketh (1555), a graphic satire on the Marian burnings – to show how visual sources contributed to public debates about religion in sixteenth century England and asks what the nature of that contribution was. Were images ‘popular’, as Robert Scribner argued was the case in Reformation Germany? Or were they intended to do more than broaden the public of a given debate? Finally, the paper considers what visual polemic like The Lambe Speaketh tells us about ongoing debates about the extent to which early modern Protestantism was iconophobic.