He spent twenty-three years in exile, from 1791 to 1814, during the French Revolution and the First French Empire, and again in 1815, during the period of the Hundred Days, upon the return of Napoleon I from Elba.
Until his accession to the throne of France, he held the title of Count of Provence as brother of King Louis XVI.
On 21 September 1792, the National Convention abolished the monarchy and deposed Louis XVI, who was later executed by guillotine.
When his young nephew Louis XVII died in prison in June 1795, the Count of Provence succeeded as (titular) king Louis XVIII.Following the French Revolution and during the Napoleonic era, Louis XVIII lived in exile in Prussia, England, and Russia.
When the Sixth Coalition finally defeated Napoleon in 1814, Louis XVIII was placed in what he, and the French royalists, considered his rightful position.
However, Napoleon escaped from his exile in Elba and restored his French Empire.
Louis XVIII fled, and a Seventh Coalition declared war on the French Empire, defeated Napoleon again, and again restored Louis XVIII to the French throne.
Louis XVIII ruled as king for slightly less than a decade.
As a constitutional monarch, Louis XVIII's royal prerogative was reduced substantially by the Charter of 1814, France's new constitution.
Louis had no children, so upon his death the crown passed to his brother, Charles X.
Louis XVIII was the last French monarch to die while still reigning, as Charles X (1824–1830) abdicated and both Louis Philippe I (1830–1848) and Napoleon III (1852–1870) were deposed.