The princely state of Salzburg, in present-day Austria, had in the early-modern era a Catholic majority and a small but visible Protestant minority. The Protestants’ visibility was not so much social as topographical: most lived in independent farmsteads on the heights above Salzburg town, leaving on occasion to work for wages in neighboring states (where pastors had introduced many of their ancestors to Lutheranism). Salzburg’s ecclesiastical rulers tolerated this heretical population throughout the 1600s, but in the second quarter of the eighteenth century Prince-Archbishop Leopold von Firmian identified them as a stain on his principality. After a failed attempt to convert the mountain-dwellers to the One True Faith, in 1731 Leopold invoked the doctrine cuius regio, eius religio and expelled his Protestant subjects. He relented only to the extent of allowing the expellees a little extra time to sell their lands and property before deportation. In the spring and summer of 1732, thirty thousand men, women, and children went into permanent exile from their homeland.
Konstantin Cretius, The Salzburgers Received,1860
The other princes of the Holy Roman Empire did nothing to stop Leopold, for in challenging him they might undermine their own prerogatives. Moreover, some of these potentates wanted the subjects the prince-archbishop was discarding. One third of the expellees settled in Holland or Hanover, or in the new colony chartered by and named for the Elector of Hanover (in his capacity as King of Great Britain), Georgia. Most of the Salzburg Protestants, however, sought refuge in the far east of Germany, near the Prussian city of Konigsburg. King Frederick William, pleased to enlarge his kingdom’s future base of taxpayers and army recruits, offered the refugees land, travel funds, and a temporary tax abasement, and twenty thousand of them accepted his offer. To their new homeland they followed a clockwise route around the mountains: west to Ulm, north to central Germany, then east to Prussia. King Fred-Bill personally greeted the first emigrant party outside of Berlin, and joined them in prayer and song. He doubtless saw the arrival of so many new subjects as providential, while understanding that the migration was entirely the work of men - in particular of two men, a religious bigot and the constructive opportunist the king so frequently saw in his mirror.
Sources: Mack Walker, The Salzburg Transaction: Expulson and Redemption in Eighteenth-Century Germany (Cornell UP, 1992); Julie Sweet, Negotiating for Georgia (U. Georgia, 2005), 106-107.