Yeah, you know, after Han Solo blasts Vader away from the Death Star trench in the Battle of Yavin, Vader crashes into a planet he had never seen before, it was not in the charts.
He gets out of the Tie Fighter and sees some little beings he finds obnoxious. So he decides to go to the South East, where he finds a Nazgul, who he chokes, starting a war against Mordor.
The Galactic Empire vs Mordor. Cheap Comic Title. Anyway, there's a war in which they reach a peace agreement through a gift from the Empire to Sauron. It was a clone of Count Dooku.
"He's a Jedi", they told Sauron, rename him, and he shall be powerful, so Sauron renamed Dooku's clone Saruman, and the Empire left Middle Earth, to start looking for the Rebels again.
They send probe droids all across the galaxy, one falls in an apparently inhabitable frozen world...
*The Empire Strikes Back takes off*