In 1690 the Palatine Prince converted to Catholicism, and he started a persecution of religious sects like Mennonites and Dunkers, in his attempt to convert them to Catholicism. Because of this persecution, German emigration became substantial.The first of the immigration waves was characterised by religious pietist sects like the Mennonites and Dunkers. In the 1720s a larger wave of immigrants of the Lutheran and Reformed Churches moved, it may seem as they left for more economic than religious reasons. Soon other German groups like the Moravians and the Amish people moved.
The Elector Palatinate made vigorous protests at these departures and published an edict of death to all emigrants. It is unclear whether these threats were fulfilled, but, because of this edict, many departed under cover of darkness. One phase of Palatine emigration began in the spring of 1709 and an estimated 14,000 were camped in Britain in Blackheath, Greenwich Heath and other sites near London. Conditions were appalling and the British found that they were unprepared for the numbers that had crossed their border. Some of these emigrants resettled in Ireland but without the free land they had been guaranteed. Approximately 3000 Roman Catholics that had emigrated were sent back to Germany, upwards of 1000 went to Jamaica, the West Indies and South Carolina.