His studies were interrupted at the age of 21, when France became involved in World War I and Julia was conscripted to serve with the army.

His many operations to remedy the situation were all unsuccessful, and for the rest of his life he resigned himself to wearing a leather strap around the area where his nose had been.

Julia gained attention for his mathematical work at the age of 25, in 1918, when his 199-page Mémoire sur l'itération des fonctions rationnelles ("Memoir on the Iteration of Rational Functions") was featured in the Journal de Mathématiques Pures et Appliquées.

[5] He was suspended for a few weeks after the liberation of France,[6] but according to Michèle Audin:[7] This was followed by no sanction, as the epuration committee was (unanimously...) too impressed by his status of "gueule cassée" to do anything.

Then he resumed his normal activities, professor at the Sorbonne and l'Ecole Polytechnique, was president of the Académie des Sciences in 1950, etc.