The original purpose of this monograph was to tell the European half of the story of William Penn's relations with the Dutch Quakers who emigrated to Pennsylvania. But the predominance of the Dutch Quaker pioneers, as revealed by that story, in the settlement of Germantown made it desirable to follow them across the Atlantic and indicate the part, which they played for at least a quarter-century in the affairs of the Quaker colony. "Hence the study comprises, first, Penn's efforts on his three journeys to Holland and Germany to convert to Quakerism the Labadists, Pietists and Quietists whom he found there; second, the way in which small Quaker communities on the Continent had prepared the way for these visits; and finally, the rise and progress of those congregations of Dutch and German Quakers who, fleeing from persecution, accepted Penn's invitation to settle in Pennsylvania.