Disciplina is the deified personification of discipline. She appears to be a late invention from Imperial times originating in the time of the Emperor Hadrian, who reigned from 117 to 138 CE, and Hadrian is probably to be credited with inventing Her. Disciplina was worshipped primarily by soldiers, especially those on the frontiers of the Empire; the earliest known dedication to Her is from the town of Chesters, near Hadrian's Wall, the great defensive barrier built to keep the Picts out of Brittania. Hadrian reformed the military during his reign; though he had officially abandoned the policy of conquest, he instituted new regulations and stricter training that kept the army always at the ready. This act was commemorated on coins from his era, which do not usually depict Disciplina as a Goddess, instead showing Hadrian in a military cloak leading several soldiers. They are labelled DISCIPLINA AVG, meaning "the Discipline of the Emperor".

Several other altars dedicated to Disciplina have been found in military outposts in Britain, all from either the north of England or from Scotland, the northernmost limits of the Empire, and most of which date to the time of Hadrian (though some are later). Other inscriptions to Disciplina have been found in northern Africa, representing the southern limit of the Empire, and it would seem that Discipline was especially emphasized or enforced way out in the boonies, where the soldiers were far from the organized center of the Empire and surrounded by barbarians with their foreign, non-Roman ways.

The Latin word disciplina was especially used to refer to military training, but could also mean "education", "ordered way of life", or refer to the results of training; and it was also used in the modern sense of "body of knowledge" or "science", such as is applied to a philosophical or scientific study or system. This Discipline of the Emperor glorified the difficult and demanding training Roman soldiers went through, and their pride in remaining Roman in strange lands, as well as reminding the soldiers of their connection with home.