Ernest Courtot de Cissey was born in Paris, educated at the Prytanée National Militaire and, after passing through St Cyr, entered the army in 1832, becoming captain in 1839.

He took part as a colonel in the Crimean War, and after the battle of Inkerman received the rank of general of brigade.

He was released from captivity only at the end of the war, and on his return was at once appointed by the Versailles government to a command in the army engaged in the suppression of the Commune.

He occupied this post several times during the critical period of the reorganization of the French army, and served briefly as Prime Minister of France from 1874 to 1875.

In 1880, whilst holding the command of the XI corps at Nantes, he was accused of having relations with a certain Baroness Lucie von Kaulla (1840–1891?