Complex sentence: The succession then went to the children of the morganatic second marriage of Grand Duke Karl Friedrich and Louise Karoline Geyer von Geyersberg, who was created Countess of Hochberg in the Austrian nobility at the personal request of Karl Friedrich.
Split into simpler sentences: The succession then went to the children of the morganatic second marriage of Grand Duke Karl Friedrich and Louise Karoline Geyer von Geyersberg. She became Countess of Hochberg in the Austrian nobility at the personal request of Karl Friedrich.