Final answer:
Ferdinand and Isabella of Spain financed Columbus's voyages amidst skepticism about his plans due to the potential for religious expansion and commercial dominance over Portugal, but their private beliefs on the matter are not detailed in the resources.
Step-by-step explanation:
The king and queen of Spain, Ferdinand and Isabella, initially rebuffed Christopher Columbus's request for funding of his voyage due to skepticism from their nautical experts about his miscalculated width of the Atlantic Ocean. However, driven by the goals to expand Catholicism and achieve commercial dominance over Portugal, they ultimately financed the expedition.
Despite their concern regarding the inaccuracies in Columbus's calculations and the potential risks of the voyage, the chance to gain a commercial advantage and spread Christianity swayed them to support Columbus.
It is not explicitly stated in the provided texts what the king and queen secretly believed about Columbus's voyage, but it can be inferred that they harbored doubts about his underestimation of the journey to Asia.
Nonetheless, after the completion of the Reconquista, the allure of potential great gains for God and Castile, and the lure of gold, silver, spices, and the possibility of claiming new lands were strong motivators that led them to overlook Columbus's egotistical demeanor and demands for great personal rewards.
Queen Isabella, in particular, displayed a willingness to support Columbus's enterprise, with the hope of accumulating wealth and spreading religious influence. Despite the opposition from many nautical experts, the king and queen's decision was influenced by the competitive nature of the era's exploration and the pressure to outpace Portuguese advances in reaching Asia.