On the French Revolution, Damas-Crux backed the king and emigrated - part of the Vexin regiment came to join him from the Principality of Monaco and these men fought under his command in the 1792 campaign.
In 1793 he raised the émigré 'Légion de Damas', leading it on the campaigns that year in the Netherlands.
When the French Revolutionary Army invaded the Netherlands, the legion passed into British pay.
The unit wished to land in western France, but this led to its infantry being largely destroyed on 21 July during the Quiberon expedition.
In 1796 Damas-Crux concluded a surrender with the Prince of Condé that allowed Damas-Crux to form a squadron of hussars out of the remains of his legion - he then commanded this squadron as part of the Army of Condé.

In 1795 Louis XVIII (or the Count of Artois) had promoted Damas-Crux to maréchal-de-camp.
He followed Condé's army to Poland in 1801 and he and Condé joined the Russian army the following year.
Damas-Crux was the Duke of Angoulême's attaché in Russia, as first gentleman of the chamber, and accompanied him from Mittau to join Condé's army, then to Warsaw and finally to England.
On the French Revolution, Damas-Crux backed the king and emigrated - part of the Vexin regiment came to join him from the Principality of Monaco and these men fought under his command in the 1792 campaign. In 1793 he raised the émigré 'Légion de Damas', leading it on the campaigns that year in the Netherlands. When the French Revolutionary Army invaded the Netherlands, the legion passed into British pay. The unit wished to land in western France, but this led to its infantry being largely destroyed on 21 July during the Quiberon expedition. In 1796 Damas-Crux concluded a surrender with the Prince of Condé that allowed Damas-Crux to form a squadron of hussars out of the remains of his legion - he then commanded this squadron as part of the Army of Condé.
In 1795 Louis XVIII (or the Count of Artois) had promoted Damas-Crux to maréchal-de-camp. He followed Condé's army to Poland in 1801 and he and Condé joined the Russian army the following year. Damas-Crux was the Duke of Angoulême's attaché in Russia, as first gentleman of the chamber, and accompanied him from Mittau to join Condé's army, then to Warsaw and finally to England.
Étienne-Charles de Damas-Crux