Question:
Which position did Charles-Joseph, 4th Duke d'Ursel hold in Aug, 1829?

Context:
 Charles-Joseph, 4th Duke d'Ursel holds the position of Minister of State from Jan, 1829 to Jan, 1830. 
 Charles-Joseph, 4th Duke d'Ursel holds the position of Minister of Transport, Public Works and Water Management from Sep, 1815 to Jul, 1819. 
 Charles-Joseph, 4th Duke d'Ursel holds the position of mayor of Brussels from Jan, 1810 to Jan, 1814. 
 Charles-Joseph, 4th Duke d'Ursel holds the position of interior minister from Jan, 1814 to Jan, 1815. 
 Charles-Joseph, 4th Duke d'Ursel holds the position of Senator of Belgium from Jan, 1839 to Jan, 1859.

Answer:
Minister of State