At the outbreak of the
Bohemian Revolt and the
Thirty Years' War, in 1618, Dietrichstein fled to
Vienna but returned after
Emperor Ferdinand II's decisive victory at the
Battle of White Mountain and was appointed Governor of
Moravia from 1621 to 1628. Due to the ongoing conflict he did not participate in either the
1621 or
1623 papal conclaves. He became responsible for implementing the
Counter-Reformation in Bohemia and surrounding regions and for mediating internal
Habsburg disputes. In 1624, he was elevated as
Fürst (Prince)
von Dietrichstein zu Nikolsburg, a hereditary title he could pass on to his nephew
Maximilian and his legitimate male descendants. The Ditrichstein family went extinct with the death of the last
Fürst in 1864. In 1868, the title of Fürst von Dietrichstein zu Nikolsburg was recreated in the
Austrian Empire for
Count Alexander von Mensdorff-Pouilly, the husband of Countess Alexandrine von Dietrichstein-Proskau-Leslie (1824–1906), reviving the title previously held by his wife's family. Prince Alexander was first cousin to both
Queen Victoria and her husband,
Prince Albert of Saxe-Coburg and Gotha. In 1635, Franz Seraph was banished from court and all of his possessions were confiscated, but the dispute was resolved later that year, his properties and titles were restored and he was appointed
Cardinal-protector of the
Holy Roman Empire. The following year he was also appointed Imperial governor in
Moravia,
Bohemia and
Lower Austria. == Private life ==