Complex sentence: During the Thirty Years War Lorsch and its neighbourhood suffered greatly; in 1621 most of the buildings at Lorsch were pulled down; having again come into the possession of the archbishopric of Mainz, the region was returned to the Catholic faith.
Split into simpler sentences: During the Thirty Years War Lorsch and its neighbourhood suffered greatly; in 1621 most of the buildings at Lorsch were pulled down. Having again come into the possession of the archbishopric of Mainz, the region was returned to the Catholic faith.