He rose through the ranks to Admiral, and commanded the Far East naval division during the Paknam incident.

[1] His parents were Jules Humann (1809–1857), a diplomat, minister plenipotentiary and peer of France, and Isabelle Hortense Guilleminot (born 1811).

[4] He served as aide de camp from 1865 to 1867 with the admiral commanding the China Sea Division.

[4] In February 1871 he was gunnery officer under Admiral Louis Pierre Alexis Pothau, Minister of the Navy.

In 1887 he returned to the Newfoundland station commanding first the Clorinde and then the Clochetterie, using diplomacy to resolve the many problems of the fisheries.

[3] At this time Britain and France were extending their spheres of influence in Southeast Asia.

The British had taken control of Burma and the trans-Mekong Shan States, while France had established a protectorate over Annam (central and southern Vietnam).

The independent kingdom of Siam (Thailand) lay between the two colonial powers, and could potentially serve as a buffer.

[9] In late June three French gunships appeared at the mouth of the Menam River to the south of the Siamese capital of Bangkok.

The French soon apologized and the two powers settled down to protracted negotiations over buffer zones and borders.

[13] The French government claimed that Humann's actions were in defiance of (or due to failure to receive) orders instructing him not to enter the river.

In October 1897 he was given command of the Western and Levantine Mediterranean Squadron, with the battleship Brennus as his flagship.