In the European race to colonial dominance, the Treaty of Tordesillas legitimized Spain’s holdings in the New World, indicating Spanish primacy over Portugal.The successes of Columbus ushered in an era of Spanish conquest that led numerous other European explorers to attempt similar colonization projects.Spain gained immense wealth from this expansionism, which translated into an influx of Spanish art and cultural capital.
Summary: They wanted political power because if you had an empire big enough you would have more power and control and they wanted to spread Catholicism and gain favor with the pope.
