In the erection of public works this was a notable era in all the kingdom of Aragon. A number of bridges were built, and tolls were collected to provide for their preservation and repair. The Catalans were particularly mindful of improving their ports. That of Barcelona was enlarged in the fourteenth century, and in the fifteenth an artificial port was begun and completed. The fifteenth century also marked the beginning of work on the artificial port of Valencia. Old roads were improved and new ones built. A considerable advance was made in works of irrigation in all parts of the realm. In this respect Valencia took the lead, making use of the canals dating from the Moslem period, but amplifying and improving them. A mail service developed at this time. The kings and the municipalities had their separate mails, but in Catalonia there was also a private mail-carrying industry as early as the latter part of the thirteenth century. CHAPTER XVI INTELLECTUAL PROGRESS IN SPAIN, 1252-1479 _Castile_ [Sidenote: Beginning of Castilian intellectual superiority in the peninsula.] [Sidenote: General characteristics of the era.] With the advance of the Christian conquest against the Moslems the political centre had passed from the northern coast to the Castilian table-land, and thence to Andalusia, where for a time the court was set up in Seville. There was a tendency, however, to return to Castile proper, since the people of that region were the principal element in the conquest and in internal political affairs. The political preponderance of the Castilian part of the realm was so clearly established that it transformed that region in many ways, and caused it to have for the first time a civilization superior to that of the coastal plains, overcoming the geographical handicaps which hitherto had held it back. The predominance of Castile in intellectual life was to become yet more marked in later centuries. In earlier times the rude Asturians and Galicians had joined with the no less rude Leonese and Castilians against the Moslems, but they had become modified by contact with the conquered people themselves and with the various foreigners who joined them in the conquest. The indigenous people did not lose their own individuality, however; rather they assimilated the new influences, and paved the way for the brilliant and original manifestation of intellectual culture of the sixteenth and seventeenth centuries. The principal characteristic of this epoch was the desire for knowledge, leading to the incorporation into indigenous civilization of many other elements. The conquest of Andalusia brought Castile into more intimate contact with Moslem civilization, which reached its culminating point in science and in art in the fourteenth century. French elements continued to affect polite literature and didactic works. Especially noteworthy was the great prominence of the influences coming out of