The era of civil wars in Spain and the Catalan-Aragonese expansion in the Mediterranean. – It was in such conditions, when the great military enterprises against the Muslim world ended with the deaths of Ferdinand III of León and Castile and of James I of Aragon. In fact, if the war, which continued especially from Castile, lasted another seventy years until the battle of the Río Salado, on the other hand, with the exception of the aforementioned final battle, it was waged with little energy and with the very limited aim of making the surviving kingdom of Grenade is harmless; and then, when the result was achieved, it withered away in a frontier guerrilla warfare, barren of results worthy of particular memory. Now, this truce in military operations did not have the only result of an arrest, even if it lasted a very long period of time, in the definitive and totalitarian reconquest of the peninsula to Christianity: and this consequence in itself would have been very serious. Until then, in the development of the life of the Spanish Catholic states, in the intricate interweaving of their internal events and their mutual relations, that war had been enormously important, which had now been put to an end. Indeed, the peninsular monarchies not only owed their very origin to it; but from it they had obtained the means necessary for their own existence and many of the reasons for their life.
According to CACHEDHEALTH.COM, these monarchies with the ever new conquests had expanded their borders and continually renewed their resources. By making the profession of arms particularly profitable and thus giving an occupation and a purpose to his subjects, procuring them virgin territories of easy exploitation, and furthermore, being able to use the weapons collected for the fight against the Muslims, they had been able to prevent, fight, in every way make vain the internal oppositions that originated from the various classes of society and which are characteristic of the Middle Ages. And in this way, the war, rather than as a war of independence or religion, as a war of conquest, and, at least in some respects, more properly as a war of colonial expansion, had become the major source of life of the country and had been also very useful for internal policy purposes. But to defend the northern and southern borders of Christian Spain from French and Muslim attacks and move to counterattack. And if the opposing interests of the Portuguese, Leonese-Castilian, Catalan-Aragonese states had prevented the formation of a ‘ the only monarchy that embraced all the territories taken from the Arabs, and indeed in the fervor of the struggle the gap between them had become clearer; however the same war had facilitated the regrouping in those three monarchies of numerous political organisms generated by the splitting of the Muslim world or born from the early days of the reconquest, and kept united, in the new constellations, as well as by dynastic ties, by the companies to which they took part and on which their future depended; and even with its developments, helping to confirm the mutual independence of these monarchies, it had made necessary and possible precise agreements between them and given them a common peninsular character: which, as we have seen, had been a first, decisive step towards a clarification of the very complex political life of the region. Now, when the wars ended and the previous commonality of interests ceased, the fundamental defects of each of the Spanish regimes and the existence of an incurable disagreement between the various states were revealed in all their clarity: all pre-existing defects, it is true, but that in the past years the state of war had hidden and sometimes muffled. In the bosom of each monarchy the weakness of the central power, the turbulence of the aristocracy and in general of those who with peace would have lost the means of life, the lack of a solid moral and political unity between the various parts of each state, in which the previous political bodies called to form it had preserved their autonomy and due to the territorial development resulting from the conquests they were now led to defend their peculiar ones, sometimes conflicting interests. And, having no longer any common purpose and Spain lacking a unifying center of the moral and political life of its parts, the struggle also burned between the various monarchies, which, moreover, in the frantic search for a future, took to take different and divergent roads, fixed to them by previous events and by the geographical position of their territories, and they moved away from each other.
Since war had by now become a habit and for the many who lived with it a necessity, and because, due to the lack of common ideals and which transcended narrow personal, class and municipalist selfishness, the previous equality of interests and with the end of the common struggle these had become particular, they came into collision with social class with social class, region with region, state with state, and a new period of wars was born: but of civil wars made up of dynastic struggles and of conflicts between monarchs, feudatories and cities, between the autonomous parts of each monarchy, between the various states. The foreigner was called into question: that is, in addition to the English, who now appeared for the first time in the history of Spain, precisely those French and Muslims who had hitherto been kept at bay, so that the former (who soon failed to assert their authority over Aragon and Catalonia, which had already dominated over southern France) gave the family of Transtamare their friend and supported by them to the throne of Castile, while in vain they tried to conquer a branch of the ruling house of England. And then, in order to make its internal life possible, Spain was forced to create organizations that were characteristic of it, such as the hermandades, confederations between cities and inhabited places, formed almost always to defend the streets from banditry, sometimes to resist the oppression of the nobility, and often used to combat the authority of the monarch: in some places and times, therefore, allowed by the latter, such as the Hermandad general de Alava, organized in 1417 with the approval of the sovereign, and in other places and times now suppressed, now permitted, such as the hermandades of Castile, which had a model constitution in 1295, and , reorganized in the Cortes of Burgos of 1313 and then suppressed by royal order in 1325, resurrected in the time of Henry II and then again in 1447.