Sixtus might jeer at Philip and urge him for his own sake to finish with the English, but Sixtus knew that the issue was as large as Christendom, and no Pope of the great post-Tridentine line was more single-mindedly devoted to the recovery of all the provinces lost since Luther to the faith. Sixtus might be loud in his admiration for the Queen of England, but he was eager to assist in her overthrow by whatever means might offer. Whatever Sixtus may have felt or said about the death of the Queen of Scots, only one question was really important to him. Would it spur the laggard King of Spain?

Garrett Mattingly, The Defeat of the Spanish A…, loc. 126