Why did King Ferdinand and Queen Isabella hesitate until 1492 to fund Columbus voyage?

King Ferdinand and Queen Isabella of Spain hesitated to fund Columbus's voyage until 1492 due to various political and financial considerations. They were preoccupied with the Reconquista, the effort to reclaim Spain from Muslim rule, which culminated in the conquest of Granada in early 1492. Additionally, they needed to ensure their resources were stable and secure before committing to an ambitious overseas expedition. Only after achieving these priorities did they feel confident to support Columbus's plans for exploration.