He was born into a noble military family. His father, Joseph Guillaume Debelle (1779-1816), was a captain in the
Grande Armée. After 1816, Alexandre was raised by his uncle,
César Alexandre Debelle (Baron de Gachetière), who became his guardian. He originally studied law at the
University of Grenoble. In 1830, he decided that he would rather be an artist and studied with
Benjamin Rolland, Curator of art at the
Museum of Grenoble. Originally a landscape artist, he devoted himself to natural scenes, with and without structures, from throughout the
Dauphiné. He later published a four-volume album of lithographs as a tourist guide to the area. In addition to his early studies, he also worked with
Antoine-Jean Gros and
Camille Roqueplan but, in 1832, failed to qualify for admission to the
École des Beaux-Arts in Paris. He returned home and exhibited at the Salon there. Finally, in 1837, he was able to exhibit at the
Louvre and moved back to Paris, where he continued to exhibit until 1848. After 1839, he switched mostly to history painting; primarily scenes from the
Revolutionary period. These would become his best-known works. In 1853, upon Rolland's retirement, he was appointed Curator at the Museum of Grenoble and remained there until 1887, when he was eighty-two years old. While there, he promoted the work of local artists; including
Jacques Gay,
Jean Achard,
Henri Blanc-Fontaine,
Diodore Rahoult and
Théodore Ravanat. In the 1860s, he was able to travel extensively throughout the Mediterranean region, producing several paintings of North Africa. From 1870 to 1872, he and librarian organized the museum's move to a new building, designed by
Charles-Auguste Questel (now known as the Musée-bibliothèque de Grenoble). == References ==