Complex sentence: It also included cities such as Perpignan which then formed part of the Catalan political and cultural domain; in some ways the Jewish traditions of Catalonia were closer to those of Provence than to those of Castile and southern Spain.
Split into simpler sentences: It also included cities which at that time formed part of the Catalan political and cultural domain, such as Perpignan. In some ways the Jewish traditions of Catalonia were closer to those of Provence than to those of Castile and southern Spain.