Valencia at the time of its conquest in the thirteenth century received a constitution modelled on that of Catalonia. The land was shared among the great nobles: its Saracen cultivators became their vassals, and the main source of their wealth and power. In the towns a mixed and busy Christian population sprang up, drawn from Italy and France as well as from Catalonia and other provinces of Spain.
Of the three Basque provinces Biscay was a semi-independent principality until the end of the fourteenth century, when marriage made the King of Castile its Sefior. Alava and Guipuzcoa were originally behetrfas; the Kings of Castile became their overlords after the beginning of the thirteenth century. The former was incorporated as a province of Castile in 1332. While the local liberties of other provinces were sacrificed to the centralising policy of Ferdinand and Isabel, the Basques of Biscay and Guipuzcoa, owing partly to respect for tradition, and partly to the necessity of securing the loyalty of a frontier people, obtained the confirmation of their privileges and the right of self-government. Their contribution to the revenue was a "free gift" granted only after redress of grievances. In royal decrees they are called "a separate nation"; as such they upheld their freedom from direct taxation and their right of bearing arms,—the special marks of nobility. It is to be noted that certain Castilian towns enjoyed a similar privilege.
The first two years of Ferdinand and Isabel's reign were occupied by a war of succession. Many of the Castilian grandees, supported by the Kings of Portugal and France, maintained the claim of Juana, called la Beltraneja, whom Henry IV had acknowledged as his daughter and successor, but whose legitimacy was doubtful. Aragon took no share in the war; for in this kingdom Ferdinand had not yet succeeded his father. The Portuguese and the Castilian malcontents overran the western frontier, and seized Burgos and strong positions in the Douro valley. The battle of Toro (1476) put an end to the danger, and left leisure for reforms. During the two preceding reigns Castile had been given up to anarchy; the municipalities had become almost independent; the nobles had usurped the privileges of royalty and devastated the country by their private wars. Centralisation, repression, and assertion of the supremacy of the Crown, were the remedies applied. The primary need was personal security. Outside the walls of the towns all men were at the mercy of the lawless nobility, or of robber bands. As far back as the thirteenth century the municipalities of Castile had formed leagues or "brotherhoods" for defence in time of war, or to resist encroachments by Kings or nobles. Isabel's first parliament (Madrigal, 1476) revived and generalised this practice by founding the Holy Brotherhood. Throughout Castile each group of a hundred houses furnished a horseman for the repression of crimes of violence in the open country and for the arrest of criminals who fled from the towns. Judges of the Brotherhood resided