 In 1492, under the Catholic Monarchs, the first edition of the "Grammar of the Castilian Language" by Antonio de Nebrija was published.In the 15th century, the most important among all of the separate Christian kingdoms that made up the old Hispania were the Kingdom of Castile (occupying northern and central portions of the Iberian Peninsula), the Kingdom of Aragon (occupying northeastern portions of the peninsula), and the Kingdom of Portugal occupying the far western Iberian Peninsula.The rulers of the kingdoms of Castile and Aragon were allied with dynastic families in Portugal, France, and other neighboring kingdoms.