Complex sentence: He and his family, who had been held captive by the Swedes in Riga, were moved to Ivangorod, Russia, and held there between 1658 and 1660.
Split into simpler sentences: He and his family, who had been held captive by the Swedes in Riga. They were moved to Ivangorod, Russia and held there between 1658 and 1660.