Charles Mathieu Isidore Decaen

Charles Mathieu Isidore Decaen (13 April 1769 – 9 September 1832) was a French Army officer and colonial administrator who served as the governor of Isle de France from 1803 to 1810.

In 1796 he served under Moreau in the operations near the Rhine and he distinguished himself in the passage of the river and the siege of Kehl, for which he was awarded a sword of honor by the French Directory.

Possibly singled out for "exile" by Napoleon Bonaparte for his association with Moreau's Army of the Rhine, Decaen was sent on a difficult mission to the French establishment in India in 1802.

He released Matthew Flinders from house arrest in April 1810, a few months before the Battle of Grand Port (August) and the capitulation to the British on 3 December of the same year.

Decaen made an unsuccessful effort to maintain the royal authority in that city after the return of Napoleon I from Elba in 1815.