when isabella’s brother died, she was supposed to be the new queen. her brother enriques’s daughter, juana, wanted to become queen instead. after a war, isabella became queen. at the same time, isabella’s husband, ferdinand, became king of aragon. they united the lands of castile and aragon into present-day spain. isabella helped pay for four of christopher columbus’ trips to find the americas. in their time, the americas were called “the new world”. she signed a truce in 1492 that made spain a christian country. after she died, her daughter joanna of castile became queen.