Background
The Battle of Hoth is a fictional battle occurring at the beginning of the movie Star Wars Episode V: The Empire Strikes Back. The Battle of Hoth is thematically unlike the epic battles of Yavin and Endor in that it occurs at the beginning, rather than the end of the movie. This means the story elements that occur in Empire are the effects of the this battle, rather than the events that lead up to it.
After the destruction of the Death Star, the Galactic Empire redoubled its efforts to destroy the Rebel Alliance. Not only did they prove themselves a credible threat to their rule of the galaxy, which would draw additional allies to their side, but Darth Vader became aware of Luke Skywalker, a Jedi in training, after nearly shooting Skywalker down during the third and final Death Star trench run. It was his developing Jedi skills that allowed Skywalker to overcome the electronic countermeasures that rendered his X-Wing's targeting system useless, and he was able to manually aim his proton torpedoes into the massive battle station's one small vulnerable spot, destroying the entire station and everyone on it. Darth Vader, being the sole Imperial survivor, saw the potential of the young Jedi and sought to either convert him to the Dark Side of the Force or kill him.