Léonard-Léopold Forgemol de Bostquénard was born on 17 September 1821 at Azerables, in the Creuse department.

He graduated from the military school of Saint-Cyr in 1839 and was posted to Algeria in 1840 as an infantry lieutenant, eventually attaining the rank of colonel.

Provisionally promoted to brigade general on 30 January 1871, Forgemol was confirmed in this rank the following September.

An injury that he received during the war obliged him to wear a large silver plastron over his abdomen.

[citation needed] In 1881, when he was in command of the army for the region of Constantine, Algeria, Forgemol was ordered by the government of Jules Ferry to direct the military operations in Tunisia from April to July 1881.