"Protestants in Masquerade" is the twelfth chapter of my biography of Thomas, 5th Baron, 1st Earl, and 1st Marquess of Wharton. It deals with the emergence of the Whig party, of which Wharton was to become a famous leader, and the attempt to exclude James, Duke of York, from the throne of England. My story covers the period from the parliamentary elections of August 1679 to the dissolution of the "Second Exclusion Parliament" in January 1681. It is an installment in the political education of then-young Tom Wharton as well as an account of a great crisis in English government. The narrative will be more meaningful to readers familiar with Restoration politics and with the chapters which have preceded this one (particularly Chapters ...