Final answer:
The earliest known date of a woodcut portrait of Dracula in German pamphlets is not provided in the given information. Albrecht Dürer's work is mentioned, indicating the importance of woodcut as an art form during the Renaissance, but further research is required for a specific date.
Step-by-step explanation:
The date of the earliest known woodcut portrait of Dracula in the German pamphlets is not explicitly mentioned within the provided information. However, the provided content highlights the work of Albrecht Dürer, a notable German woodcarver, painter, and printmaker from the Renaissance period.
Dürer's influence on printmaking and his renowned woodcuts, such as the Four Horsemen of the Apocalypse from around 1497-98 and St. Jerome in His Study from 1514, demonstrate the significance of woodcut as an art form during his time. To find the specific date of Dracula's earliest woodcut portrait, additional research on works postdating Dürer's era or direct references to Dracula-related pamphlets from that time would be necessary.