The First Empire was the period in French history between
1804 and
1814
during which
Napoleon Bonaparte ruled as
Emperor. Although
Napoleon was forced to abdicate in 1814, he returned to power in March
1815 and reestablished himself as Emperor. This second
reign,
called
the Hundred Days, only lasted until June and is not
considered part of the First Empire period.
As you probably guessed, there is a Second Empire as well.