<span>The pre-condition which had to be accomplished on the iberian peninsula before portugal and spain could unify internally as nations is to break Islamic rule. It is so because most of the iberian is controlled by the Moors, an Islamic people who conquered most of Spain and Portugal. Without the Moors removed, the rulers of both Spain and Portugal are nothing more than usurpers to power, guerillas if you will.</span>
<span> Periodization can help historians know when an event occured. This can also help historians learn the cause and effect of another time in history.</span>