His younger brother, Jean Maurice was Lucet oil entrepreneur, his company had to manage, the Port of Bordeaux.

Ernest Charles Lucet studied law at the École libre des sciences politiques.

In 1935, he was in the North America division of the French Foreign Ministry at the Quai d'Orsay, and was sent to attache to the embassy in Washington, where he was promoted to Counsellor.

In November 1942, he was dismissed by the Vichy regime, he was followed by this recall, and did not join the exile government of de Gaulle, for which he was accredited to February 1943 in Washington.

From 1955 to 1959, he was counsellor at the French embassy in Washington under Maurice Couve de Murville and Hervé Alphand, during the Dwight D. Eisenhower administration.