I. A province of Spain, in Andalusia, bordering on New Castile, Murcia, Granada, and Cordova; area, 5,184 sq. m.; pop. in 1870, 392,100. The N. part is entirely filled with the ridges of the Sierra Morena; the central is an irregular valley, in which several streams unite to form the Guadalquivir. The soil is fertile, but little cultivated. The province produces grain, wine, fruits, oil, honey, and various minerals, and abounds in cattle and fine horses; silkworms are bred there. The trade, however, is not extensive. Among the principal towns are Andujar, Alcala la Real, Baylen, and Ubeda. II A fortified city, capital of the province, on the river Jaen, 40 m. N. of Granada; pop. about 23,000. The new town stretches beyond the walls into the plain along the river. It has two cathedrals, the principal of which occupies the site of a Moorish mosque which was demolished in 1492. A new plaza de toros was built in 1847. Jaen has been a bishopric since the 13th century, when the Moors were expelled from the city. The place is poor notwithstanding its fertile environs.

In 1808 it was sacked by the French.