Banjaluka (sometimes written Banialuka, or Bainaluka), the capital of a district bearing the same name, in Bosnia. Pop. (1895) 13,666, of whom about 7000 were Moslems. Banjaluka lies on the river Vrbas, and at the terminus of a military railway which meets the Hungarian state line at Jasenovac, 30 m. N.N.W. Banjaluka is the seat of Roman Catholic and Orthodox bishops, a district court, and an Austrian garrison. It is at the head of a narrow defile, shut in by steep hills on the east and west but expanding on the north to meet the valley of the Save. A small stream called the Crkvina enters the Vrbas from the north-east and in the angle thus formed stand the citadel and barracks, with the 16th-century Ferhadiya Jamia, largest and most beautiful of more than 40 mosques in the city. The celebrated Roman baths are all in ruins, except one massive, domed building, dating from the 6th century and still in use, although modern baths are also open, for the development of the hot springs. Other noteworthy buildings are the Franciscan and Trappist monasteries, a girls' school, belonging to the Sisterhood of the Sacred Blood of Nazareth, a real-school and a Turkish bazaar.

Coal, iron, silver and other minerals are found in the adjoining hills; and the city possesses a government tobacco factory, a brewery, cloth-mills, gunpowder-mills, a model farm and many corn-mills, worked by the two rapid rivers.

Banjaluka is probably the Roman fort, marked, in the Tabula Peutingeriana, as Castra, on the river Urbanus and the road from Salona on the Adriatic to Servitium in Pannonia. The origin of its later name, meaning the "Baths of St Luke," is uncertain. In the 15th century, the fall of Jajce, a rival stronghold 22 m. S., led to the rapid rise of Banjaluka, which was thenceforward the scene of many encounters between Austrians and Turks; notably in 1527, 1688 and 1737. No Bosnian city had greater prosperity or importance in the last half of the 18th century. In 1831, Hussein Aga Borberli, called the "Dragon of Bosnia," or Zmaj Bosanski, set forth from Banjaluka on his holy war against the sultan Mahmud II. (See Bosnia.)