[1] He was the son of the architect Leopold Ernst and, encouraged by his father, began studies at the Academy of Fine Arts Vienna at the age of fifteen.

He spent some time in Rome, copying the old masters, and continued his lessons in Vienna with August Eisenmenger and Anselm Feuerbach.

[2] In 1905, he moved to Fontenay-aux-Roses where he set up a shop to produce faience tiles with orientalist themes.

He began as genre painter but, from 1885, he devoted himself exclusively to paintings with orientalist motifs; especially Islamic scenes, such as the interiors of mosques.

He also painted harem scenes and portrayals of everyday life in North Africa, based on photographs and prints as well as his own memories from his travels in those regions.