Complex sentence: Ecclesiastically the province was historically divided into two Catholic prince-bishoprics, Seckau and Lavant From the time of their foundation both were suffragans of the Archdiocese of Salzburg.
Split into simpler sentences: Ecclesiastically the province was historically divided into two Catholic prince-bishoprics, Seckau and Lavant. Ever since the time of their foundation both have been suffragans of the Archdiocese of Salzburg.