The Alliance had begun developing the shield on Ralltiir, in affiliation with the planet's scientists. Following the Defense of Ralltiir, the scientists were transported to Hoth. Using the salvaged reactor from a scrapped Praetor-class Star Battlecruiser, they were able to provide enough power to raise the shield. An AT-AT piloted by General Maximilian Veers managed to destroy the shield generator with a high-powered blast.