The intercourse with England, partly through the emigration from that land under Mary's reign, partly through the coming and going of Flemings and Walloons, also opened doors to Protestant doctrine.
At first the missionaries came secretly, preaching to a few specially invited to some private house or inn.

People attended these meetings disguised and after dark.

First mentioned in the edict of 1550, nine years later the Calvinists drew up a _Confessio Belgica_, as a sign and an aid to union.

Calvin's French writings could be read in the southern provinces in the original.

Though as early as 1560 some nobles had been converted, the new religion undoubtedly made its strongest appeal, as a contemporary put it, "to those who had grown rich by trade and were therefore ready for revolution." It was among the merchants of the great cities that it took strongest root and from the middle class spread to the laborers; influenced not only by the example of their masters, but sometimes also by the policy of Protestant employers to give work only to co-religionists.