Once upon a time... (6th grade).

...there was a princess. Her name was Isabel. She was young, pretty and clever. She wanted to be a great queen, but it wasn't easy.
By that time, Spain wasn't a country as it is now. It was divided into different kingdoms. Castile was one of them, and Aragon was another. Isabel decided to marry Fernando, prince of Aragon. He was a smart and handsome young boy who wanted to be king as well. Together, they became great kings. They joined together their two kingdoms to create a bigger one. They also conquered the Muslim kingdom of Granada to join it to this kingdom. That would be Spain, just as we know it now (that's what we now as Reconquest).
Of course they didn't do only good things...but bad things as well (as the Inquisition). But kings and queens are also human.
They had 5 children: 4 girls and a boy. Here's what you have to do: could you tell me the names of these children and who did they marry? It's not difficult!! Follow the link!!

http://en.wikipedia.org/wiki/Catholic_Monarchs

Take a look at this video to learn a little more about the Catholic Kings.