dominions, and in so much furthered his ideal of centralization; in the third place to the backing of the opponents of their enemies, especially those who were hostile to the Inquisition; and, finally, and perhaps most of all, to their own superior attainments, whereby they were able to win a devoted following among all ranks of society. The successors of Philip II followed the later policy of that king, with the result that the seventeenth century was the most prosperous era in the history of the Jesuit order. [Sidenote: _Limpieza de sangre_ and the fervor of Spanish Catholicism.] One thing Spanish kings failed to do elsewhere in Europe they achieved in Spain,--their ideal of religious unity. At the same time that they were suppressing heresy they were giving a welcome to Catholics fleeing to Spain from Protestant persecution, notably to the Irish, who came to the peninsula in great numbers. The ideal of Catholic unity was carried to an excess which transcended unity itself through an extension of the institution of _limpieza de sangre_. Certificates of _limpieza de sangre_ (that is to say, sworn statements that the bearer had no Jewish, Moslem, or heretic antecedents) now began to be required for the holding of various church offices or for entry into religious orders and often also for admission to the guilds. As a matter of fact there were few families which could have withstood a close examination of their ancestry; the upper classes would almost surely have been found to contain Jewish blood, and the masses, certainly in the east and south, would have had a Moslem admixture in their veins. The attainment of religious unity and the extreme suspicion in which non-Catholics were held did not succeed in making the Spanish people respond to the moral code of their faith. Not only such licentious practices as have already been alluded to were in vogue, but also a surprising lack of reverence was displayed, as exemplified by the improper use of sacred places and sacred objects and the mixture of the human and the divine in masquerades. Nevertheless, it is not too much to say that the principal preoccupation of Spaniards in the sixteenth and the seventeenth centuries was the salvation of their souls. The worst of men would want to confess and seek absolution before they died, and many of them no doubt believed themselves to be good Catholics, even though their every-day life would not have borne inspection. One notable religious manifestation of the era was the ardent insistence of Spaniards on the mystery of the Immaculate Conception at a time when Catholics of other countries were not yet ready to accept that view. [Sidenote: Conflict of the kings with the popes in matters of temporal import.]