In 1966, he began illustrating the Bernard Prince series written by Greg, published in Tintin magazine.

Hermann began writing his own stories in 1977, starting the post-apocalyptic Jeremiah series, which is still produced today.

[1] In 1983 he began a new series, Les Tours de Bois-Maury, which is set in the Middle Ages and is less focused on action than his other works.

[2] Hermann is characterized by a realistic style and stories that are both somber and angry, with a sense of disillusion with regards to the human character in general, and current society more specifically.

[1] All of these comics have been published in French, Dutch and German: other translations are noted in the "remarks" column.