"It's a huge uninteresting brick, but it's got a charm that draws you in - it's big, bland, and ugly, but it doesn't care. It's still gonna put anything smaller than a supercruiser into an early grave."
―Anonymous UNSC crewman, on the Thermopylae-class supercarrier.
The Thermopylae-class supercarrier is a heavy command and coordination carrier utilised by the UNSC during the Great War. Beginning production in 2507, the Thermopylae is the largest, most powerful and most durable warship ever built by the Reyes-McLees Corporation. Possessing an intimidating profile, the Thermopylae was built as a response to the heaviest Covenant capital ships, which firepower easily outmatched even the most powerful UNSC ships. Equipped with two super-Magnetic Accelerator Cannons flanked by two rapid-fire frigate MACs, thousands of missiles and hundreds of individual turrets, these warships were the most powerful ever fielded by the UNSC Navy at the time. Despite this, Thermopylae is outmassed by the older Punic-class supercarriers and thus cannot carry as many ground troops or fighters, but it proved far more useful as a command ship for deep strikes into unknown Covenant territory.