In 1792, Berthier was at once made chief of staff to Marshal Nicolas Luckner, and he bore a distinguished part in the Argonne campaign of Generals Dumouriez and Kellermann. He served with great credit in the Vendéan War of 1793–1795, and the next year was made a general of division and chief of staff ("major-général") to the Army of Italy, which Bonaparte had recently been appointed to command. He played an important role in the Battle of Rivoli, relieving General Joubert when the latter was attacked by the Austrian general Jozsef Alvinczi. His power of work, accuracy and quick comprehension, combined with his long and varied experience and his complete mastery of detail, made Berthier the ideal chief of staff. In this capacity, Berthier was Napoleon's most valued assistant for the rest of his career.