In 1477, by the marriage of Mary of Burgundy to the Archduke Maximilian, son of Emperor Frederick IV., the Netherlands were united to Austria and its possessions passed to the crown of Spain. In the sixteenth century, owing to the cruel persecutions of Charles V. and Philip II. of Spain, the Netherlands became involved in a series of desperate and heroic struggles. Charles V. had, in 1522, issued a proclamation against Christians who were suspected of being lax in the faith and against Jews who had not been baptized in Gelderland and Utrecht; and he repeated these edicts in 1545 and 1549. In 1571 the Duke of Alba notified the authorities of Arnhem that all Jews living there should be seized and held until the disposition to be made of them had been determined upon. In Wageningen, in 1572, there were three Jewish families which were expelled on the occasion of a papal indulgence. In 1581, however, the memorable declaration of independence issued by the deputies of the United Provinces deposed Philip from his sovereignty; religious peace was guaranteed by article 13 of the "Unie van Utrecht." As a consequence the persecuted Jews of Spain and Portugal turned toward Holland as a place of refuge.