Task: Question Answering
Input (English): Passage: The end of the Middle Ages brought with it a waning of interest in King Arthur. Although Malory's English version of the great French romances was popular, there were increasing attacks upon the truthfulness of the historical framework of the Arthurian romances – established since Geoffrey of Monmouth's time – and thus the legitimacy of the whole Matter of Britain. So, for example, the 16th-century humanist scholar Polydore Vergil famously rejected the claim that Arthur was the ruler of a post-Roman empire, found throughout the post-Galfridian medieval "chronicle tradition", to the horror of Welsh and English antiquarians. Social changes associated with the end of the medieval period and the Renaissance also conspired to rob the character of Arthur and his associated legend of some of their power to enthrall audiences, with the result that 1634 saw the last printing of Malory's Le Morte d'Arthur for nearly 200 years. King Arthur and the Arthurian legend were not entirely abandoned, but until the early 19th century the material was taken less seriously and was often used simply as a vehicle for allegories of 17th- and 18th-century politics. Thus Richard Blackmore's epics Prince Arthur (1695) and King Arthur (1697) feature Arthur as an allegory for the struggles of William III against James II. Similarly, the most popular Arthurian tale throughout this period seems to have been that of Tom Thumb, which was told first through chapbooks and later through the political plays of Henry Fielding; although the action is clearly set in Arthurian Britain, the treatment is humorous and Arthur appears as a primarily comedic version of his romance character. John Dryden's masque King Arthur is still performed, largely thanks to Henry Purcell's music, though seldom unabridged. 
Question: What is the full name of the person Vergil rejected as the ruler of a post-Roman empire?
Output (English): King Arthur.