At the beginning of 1474, Spain was a non-existent entity composed of a series of smaller kingdoms within the Iberian Peninsula. However, Spain was subject to a process of change that led to the unification of the Iberian Peninsula under a single monarchy, which controlled the New World and large areas of Northern Europe. This process of change was stimulated by the influx of the new world and, to varying degrees, by domestic and international politics. However, the New World was not always the primary factor during this period that catalyzed the rise and maintenance of power. During this period, revenues from the New World increased, and consequently also Spain's direct dependence on it. Isabella and Ferdinand did not rely on the New World, as was the case in the last third of their reign, and as such it was seen more as an economic failure. Kilsby rightly argues that, in hindsight, the discovery of the Americas was “the greatest event since the creation of the world.” Kamen shows us that there was a change in the importance of the new world, as the Spanish controlled “Indian Globe” caused their power and Kamen rightly argues that the colonies were the lifeline of the Phillips Power. The need for the New World was entirely due to the funds provided which stimulated other factors that contributed to Spain's growing power in the time period. The discovery of the New World was a minimal factor in the development of power during the reign of Ferdinand and Isabella. . Although Isabella and Ferdinand commissioned Christopher Columbus on his voyage, this was under the guise that there was enormous wealth to be found, however the mission failed and led to Christopher Columbus returning to Castile in chains. Pendrill claims that the... center of the card... implemented. Philip further depended on his inheritance in the New World to maintain his policies and authority over his land, as demonstrated in the troubles of the Dutch Revolt. Authority throughout the period 1474-1598 was largely based on religion, and it is clear that religion caused the discovery of the new world, as the capture of Granada fueled messianic fervor, resulting in Columbus being commissioned by the Spanish . For Charles and Phillip, control of the Netherlands was only feasible by undermining the Protestant Reformation. Thus the New World was largely a growing source of power for the Spanish monarch, being the main factor for Philip in maintaining his authority, but the authority fueled by this power was due to the foundation of religious policies and marriages under Ferdinand and Isabella's reign which led to the expansion of Spanish power.