Besides the advantage of discouraging Mary's partisans by the prospect of an alliance between France and England, her situation with Philip demanded her utmost vigilance and attention; and the violent authority established in the Low Countries made her desirous of fortifying herself even with the bare appearance of a new confederacy.
The theological controversies which had long agitated Europe, had from the beginning penetrated into the Low Countries; and as these provinces maintained an extensive commerce, they had early received, from every kingdom with which they corresponded, a tincture of religious innovation.

An opinion at that time prevailed, which had been zealously propagated by priests, and implicitly received by sovereigns, that heresy was closely connected with rebellion, and that every great or violent alteration in the church involved a like revolution in the civil government.

The forward zeal of the reformers would seldom allow them to wait the consent of the magistrate to their innovations: they became less dutiful when opposed and punished; and though their pretended spirit of reasoning and inquiry was in reality nothing but a new species of implicit faith, the prince took the alarm, as if so institutions could be secure from the temerity of their researches.

The emperor Charles, who proposed to augment his authority under pretence of defending the Catholic faith, easily adopted these political principles; and notwithstanding the limited prerogative which he possessed in the Netherlands, he published the most arbitrary, severe, and tyrannical edicts against the Protestants; and he took care that the execution of them should be no less violent and sanguinary.

He was neither cruel nor bigoted in his natural disposition; yet an historian, celebrated for moderation and caution, has computed, that in the several persecutions promoted by that monarch, no less than a hundred thousand persons perished by the hands of the executioner.[*] But these severe remedies; far from answering the purposes intended, had rather served to augment the numbers as well as zeal of the reformers; and the magistrates of the several towns, seeing no end of those barbarous executions, felt their humanity rebel against their principles, and declined any further persecution of the new doctrines.
* Grotii Annal.lib.i.Father Paul, another great authority, computes, in a passage above cited, that fifty thousand persons were put to death in the Low Countries alone.
When Philip succeeded to his father's dominions, the Flemings were justly alarmed with new apprehensions, lest their prince, observing the lenity of the magistrates, should take the execution of the edicts from such remiss hands, and should establish the inquisition in the Low Countries, accompanied with all the iniquities and barbarities which attended it in Spain.