Complex sentence: In 1806, he was associated with Chateaubriand and Joseph Fiévée in the conduct of the "Mercure de France", and two years later was appointed councillor of the Imperial University which he had often attacked.
Split into simpler sentences: In 1806, he, along with Chateaubriand and Joseph Fiévée, edited the "Mercure de France". Two years later, he was appointed councillor of the Imperial University which he had often attacked.