Spanish and Portuguese empires were major world powers in the epoch of their blossoming. In fact, these empires dominated in the world and colonized a considerable part of Africa and America, while the opportunities for the development of international trade were enormous. At the same time, the power of Spanish and Portuguese empires grounded on the military power and their aggressive foreign policies aiming at the occupation of new lands which could bring them new profits. In this regard, Spanish and Portuguese empires were similar to the Roman Empire, but, what is more, similarly to the Roman Empire both Spain and Portugal suffered from a considerable gap between the ruling elite and oppressed masses, which led to irresolvable internal conflicts and undermined the international position of empires, weakened them and made them vulnerable to attacks from the part of other empires.
In actuality, the position of Spanish and Portuguese empires was very strong due to the well-developed navy and trade fleet, which allowed both empires to colonize new territories oversea, protect them and develop trade between colonies and the metropolitan state (Russell-Wood, 187). In fact, it is due to the colonization Spanish and Portuguese had reached an unparalleled level of development. At this point, these empires are similar to the Roman Empire which also tended to expansive policies and aimed at the invasion of new territories over and over again to supply the ruling elite in Rome with financial resources to maintain their authority. Moreover, Rome had the most advanced army at the epoch that gave Roman a strategic advantage over its opponents, while Spain and Portugal had even more significant military advantage compared to colonized peoples in America and Africa.
On the other hand, the territorial expansion of both Spanish and Portuguese empires led to similar effects as the expansion of the Roman Empire did. The empires needed huge army to maintain order in colonies and in occupied territories, while the army needed financial resources, which were traditionally gained from the invasion of new territories. As soon as the territorial expansion of empires stopped, because they lacked both human and financial resources, the empires had started a rapid and irrevocable downfall. At the same time, economic problems, which slowed down the territorial expansion of empires were determined internal conflicts because the ruling elite, aristocracy in Spanish and Portuguese empires and patricians in Rome, did not care about the maintenance of high standards of living of the lower classes, which constituted the overwhelming majority of the society of the empires. As a result, economic activities grew more and more ineffective since slave labor in Rome could not provide the economic growth in the empire because of the low productivity. Similarly, Spanish and Portuguese empires could not use the labor of the native population of America to boost economic development in colonies, because the local population was not accustomed to European models of agriculture, which was the basis of economy at the epoch.
As a result, the internal conflicts within empires and inability of the ruling elite to stimulate economic development resulted in the degradation of empires and their decline. Being deprived of economic ground, the empires had lost their huge territories, which they could not protect because their armies dissolved as the empires had nothing to pay them.