Ancient Henna was the Sicel centre of the cult of Demeter , and the myth placed the abduction of Persephone at Lake Pergusa just below the town — which made this mountain one of the most sacred places in the Greek world. Its position, almost unassailable, made it a fortress for every power that held Sicily: Greeks, Romans, Arabs, Normans, Aragonese.

Under Arab and then later rule the town was known as Castrogiovanni , a name derived through Qasr Ianni , and it kept that name for the better part of a thousand years.

The nineteenth century changed the place completely, and the reason was sulphur . Central Sicily held some of the richest sulphur deposits in the world, and the mines of the Enna and Caltanissetta country worked at enormous scale. The town's population doubled in the course of the century. The work was brutal, notoriously so — the carusi , child workers who carried ore out of the mines, became a national scandal.

Enna was represented in Parliament for thirty consecutive years from 1890 by Napoleone Colajanni , though it was not yet a provincial capital. That came with the decree of 2 January 1927 , which created the province of Castrogiovanni from territory of Catania and Caltanissetta — twenty comuni in all. A further decree of 27 October 1927 renamed both town and province Enna .