The name is Arabic in origin — Qal'at an-nisa , the castle of the women, by the usual reading — and the town grew beneath the Norman castle of Pietrarossa in the Sicilian interior, a country of wheat and hard living.

What transformed it was sulphur . From the early nineteenth century the deposits of central Sicily were worked at a scale that made this province, for a time, the source of most of the world's sulphur. Caltanissetta became the industry's capital, with mining companies, a stock of engineers, a technical mining school and a wealth its agricultural neighbours never saw.

The human cost was notorious. Miners worked in appalling heat and danger, and the ore was carried out by the carusi — boys, some very young, often bound to a miner under a system of debt that a parliamentary inquiry in the 1870s described in terms that shocked the new kingdom. Sicilian sulphur mining became one of the defining social scandals of united Italy.

The industry declined from the late nineteenth century as cheaper American sulphur reached the market, and collapsed in the twentieth. What followed was emigration on a very large scale, and the depopulation of the interior that continues now.

In 1927 the province lost a group of comuni to the newly created province of Castrogiovanni, today Enna.