Bust of the Roman Emperor Marcus Aurelius Antoninus, known as Caracalla. The origin of the nickname "caracalla" derives from a cloak of Celtic origin
What is the origin of the nickname Caracalla ?
The man who became emperor of Rome in 198 d. C. after the death of Septimius Severus , was his son Marcus Aurelius Antoninus Augustus, who shared power with his brother Geta.
Well, hardly anyone remembers this name, as for centuries he has been known as Caracalla.
The most important provision of his government, destined to mark an epochal turning point in the history of Rome, was the Constitutio Antoniniana, a edict with which citizenship was granted to all the inhabitants of the Empire who were of free status.
Returning to the name with which the exponent of the Severan dynasty is known, it derives from a item of clothing (see also:https://www.pilloledistoria.it/6183/storia-antica/antichi-romani-in-viaggio-moda).
In fact, the Emperor used to wear the "caracalla", a large and long military cloak equipped with a hood typical of the Celtic peoples.
For Marcus Aurelius Antoninus it became a distinctive trait to the point of being identified with it and making his person and the garment he loved most all one.
Caracalla was the first to introduce the cloak of the Gauls into the Empire, effectively launching a fashion that lasted for centuries ( Photo from :raffaelloromanelli.com).