After serving in several political offices during the early years of the French Revolution, he was executed in Paris as a royalist during the Reign of Terror in 1794.

At eighteen, Colonel Dillon married a first cousin once removed, Therese-Lucy de Rothe (1751–1782).

On 6 July 1779 a British fleet under Admiral John Byron appeared off the coast of the island and the naval engagement of the Battle of Grenada was fought.

He and his regiment participated in the invasion of Tobago, the capture of Sint Eustatius, and the siege of Brimstone Hill.

[citation needed] Dillon assumed military duties at a very difficult time for noble officers of the old army.

[5] Two weeks later Dillon was called to Paris for questioning and was ultimately arrested on 1 July 1793 despite being stoutly defended by his aide-de-camp François Séverin Marceau-Desgraviers.