Complex sentence: In 1644 he became chaplain to Prince Charles Louis, nephew of King Charles I, who was in England; from 1648 Charles Louis was able to take up his position as Elector of the Palatinate on the Rhine, as a consequence of the Peace of Westphalia.
Split into simpler sentences: In 1644 he became chaplain to Prince Charles Louis, nephew of King Charles I, who was then in England. From 1648 Charles Louis was able to take up his position as Elector of the Palatinate on the Rhine, as a consequence of the Peace of Westphalia.