1911 Encyclopædia Britannica/Jaca
JACA, a city of northern Spain, in the province of Huesca, 114 m. by rail N. by W. of Saragossa, on the left bank of the river Aragon, and among the southern slopes of the Pyrenees, 2380 ft. above the sea. Pop. (1900), 4934. Jaca is an episcopal see, and was formerly the capital of the Aragonese county of Sobrarbe. Its massive Gothic cathedral dates at least from the 11th century, and possibly from the 9th. The city derives some importance from its position on the ancient frontier road from Saragossa to Pau. In August 1904 the French and Spanish governments agreed to supplement this trade-route by building a railway from Oloron in the Basses Pyrénées to Jaca. Various frontier defence works were constructed in the neighbourhood at the close of the 19th century.
The origin of the city is unknown. The Jaccetani (Ἰάκκητανοί) are mentioned as one of the most celebrated of the numerous small tribes inhabiting the basin of the Ebro by Strabo, who adds that their territory was the theatre of the wars which took place in the 1st century B.C. between Sertorius and Pompey. They are probably identical with the Lacetani of Livy (xxi. 60, 61) and Caesar (B.C. i. 60). Early in the 8th century Jaca fell into the possession of the Moors, by whose writers it is referred to under the name of Dyaka as one of the chief places in the province of Sarkosta (Saragossa). The date of its reconquest is uncertain, but it must have been before the time of Ramiro I. of Aragon (1035–1063), who gave it the title of “city,” and in 1063 held within its walls a council, which, inasmuch as the people were called in to sanction its decrees, is regarded as of great importance in the history of the parliamentary institutions of the Peninsula. In 1705 Jaca supported King Philip V. from whom, in consequence, it received the title of muy noble, muy leal y vencedora, “most noble, most loyal and victorious.” During the Peninsular War it surrendered to the French in 1809, and was recaptured in 1814.