Castile
2 of the 7 encyclopedias on this shelf carry an entry for Castile. Both are reproduced below, so you can see where they agree and where they differ.
Collier's New Encyclopedia (1921)
an ancient kingdom of Spain, the nucleus of the Spanish monarchy, extends over a large part of the peninsula from the Bay of Biscay southward. It is divided into New Castile and Old Castile. The former (Castilla la Nueva) occupies nearly the center of the peninsula; area, 28,010 square miles. It is traversed from E. to W. by three lofty mountain chains nearly parallel to each other the Sierra Guadarrama, the mountains of Toledo, and、 Sierra Molina, and the Sierra Morena. Between these chains, which form the great watersheds of the province, lie two extensive plains or plateaux, almost without wood, and arid and barren in Dryness, indeed, is the appearance. curse of the whole country, and there is a great deficiency of method alike in agriculture and industries. The inhabitants are of a grave, manly character, with much of the old Spanish pride and probity, but devoid of enterprise, and content to live on from day to day as their fathers did before them. This ancient province now forms the five provinces of Madrid, Ciudad-Real, Cuenca, Guadalajara, and Toledo. Pop. about 2,400,000. Old Castile (Castilla la Vieja) stretches from the Bay of Biscay to New Castile; area, 25,405 square miles. It is traversed by three mountain chains the Sierra de Guadarrama, the Sierra de Deza, and the Cantabrian Mountains. It is less dry than New Castile, and grain, particularly wheat, is raised in great abundance. The pastures both of the mountains and the plains are excellent, and much merino wool is produced. Old Castile now forms the provinces of Burgos, Logroño, Santander, Soria, Segovia, Spa, Avila, Palencia, and Valladolid. Pop. about 1,900,000.
Aiton's Encyclopedia (1910)
kas-tel', a former kingdom in the central part of Spain. For a long time it was a frontier state,--a line of castles, as the name implies, against the Moors. By the marriage of its queen, Isabella, with Ferdinand, king of Aragon, in 1469, the crowns of Castile and Aragon were united. From this union sprang the modern kingdom of Spain. See Moors ; Spain ; Isabella ; Aragon