Its territory mostly coincided with that of the Duchy of Benevento, a papal enclave within the Kingdom of Naples.

In addition to the capital city of Benevento, it included a contado subdivided into 12 centers: Sant'Angelo a Cupolo, Motta, Panelli, Pastene, Maccabei, Bagnara, Montorso, Maccoli, Perillo, Sciarra, San Leucio del Sannio, San Marco ai Monti.

The principality was created by Napoleon for his chief diplomat Charles Maurice de Talleyrand-Périgord.

[1] In 1815, after the Napoleonic Wars, the town was ceded back to the Papal States.

In 1860, it joined Pontecorvo, the other southern Italian papal exclave, in being united with the new Kingdom of Italy.