Complex sentence: Elisabeth first married his on 1 January 1612 in Dresden Duke August of Saxony (1589-1615), the administrator of the diocese of Naumburg, who suddenly died at the age of 26 after only three years of marriage.
Split into simpler sentences: Elisabeth first married on 1 January 1612 in Dresden, to Duke August of Saxony (1589-1615). He suddenly died at the age of 26, after only three years of marriage.