If the Catholics really were so few and so harmless, how is one to explain the ferocious anti-Catholicism of this period? The answer lies partly in the Protestant view of Catholics and Catholicism, as it had developed over more than a century, and partly in the way that this view of Catholicism affected Protestants' interpretation of current political events. The Protestant version of history since the Reformation showed Papists as obedient slaves to the pope, whose greatest ambition was to root out Protestantism with the maximum of bloodshed and cruelty; this gave a distorted picture even of the Catholics of Elizabeth's reign, since which time circumstances had changed so that it bore only a minimal resemblance to reality. However, the myth of the bloodthirsty Papist seemed to acquire new relevance from two important contemporary developments. The first was the emergence of Louis XIV as the most powerful ruler in Europe and the self-styled champion of Catholicism. However weak the Catholics might seem in England, in Europe as a whole they were very much in the ascendant. In the words of Professor Kenyon: ‘When the Thirty Years' War ended, Protestantism had been driven out to the periphery of Europe, where it was precariously lodged in North Germany, Holland, Scandinavia, England and Scotland; all, with the exception of Holland, poor, thinly populated, second-class nations.’ The emergence in this situation of a new Catholic super-power to offset the decline of Spain made the second new development particularly ominous. From 1673 it was clear that James, duke of York, the king's brother and heir-apparent, had become a Catholic.