as a son of a Christian princess, was a strong contender to take over the ultimate power in Muslim al-Andalus. A hundred years later, King Alfonso VI of Castile, regarded as one of the greatest medieval Spanish kings, designated his son (also named Sancho) by the Muslim princess refugee Zaida of Seville, as his heir. The Reconquista was a war with long periods of respite between the adversaries, partly for pragmatic reasons and also due to infighting among the Christian kingdoms of the North spanning over seven centuries. Some populations practiced Islam or Christianity as their own religion during these centuries, so the identity of contenders changed over time. It is noteworthy that the popular hero El Cid, whose name is very much associated with the Reconquista, had at one part of his career actually fought for the Muslim rulers of Zaragoza, whom he defended from its traditional enemy, the Christian Aragon. The most important achievement of El Cid's career, the conquest of the kingdom-city of Valencia, was actually achieved in close alliance with the Banu Hud and other Muslim dynasties opposed to the Almoravids. French Emulation In 1558, the armies of King Henry II of France managed to conquer the city of Calais, which had been under English rule for centuries. Queen Mary I of England considered the loss of Calais as the greatest disaster of her reign The region around Calais, then-known as the Calaisis, was renamed the Pays Reconquis ("Reconquered Country") in commemoration of its recovery by the French. The French were certainly aware of the Spanish Reconquista, and since at the time Philip II of Spain was Queen Mary's consort, use of this term might have been intended as a deliberate snub to him. Festivals in modern Spain and Portugal Currently, festivals called moros y cristianos (Castilian), moros i cristians (Catalan), mouros e cristãos (Portuguese) and mouros e cristiáns (Galician), which all mean "Moors and Christians", recreate the fights as colorful parades with elaborate garments and many fireworks, especially on the central and southern towns of the Land of Valencia, like Alcoi, Ontinyent or Villena. Persistent effects A 2016 study found that the "rate of Reconquest"—how rapidly the Christian frontier was expanded—has persistent effects on the Spanish economy to this day. After an initial phase of military conquest, Christians states incorporated the conquered land. When large frontier regions were incorporated at once, the land was mostly