Illustrious Highness
Countess Auguste von Harrach zu Rohrau und Thannhausen (30 August 1800 – 5 June 1873), was the second spouse of King Frederick William III of Prussia. At the time of their marriage, the Harrach family was still not recognized as equal for dynastic purposes. Later, in 1841, they were officially recognized as a mediatized family (a former ruling family within the Holy Roman Empire), with the style of Illustrious Highness, which allowed them to have equal status for marriage purposes to those reigning and royal families. Thus, in 1824 when the marriage occurred, it was treated as morganatic, so she was not named Queen, but was given the title Princess von Liegnitz (modern-day Legnica) and Countess von Hohenzollern. Frederick reportedly stated that he did not wish to have another queen after Queen Louise.