Xerxes Imperium

The Xerxes Imperium (also known simply as the Empire) was the name given to what remained of the First Order following Ford Xerxes XII of Decarte's ascension to the throne. It reflected the partial recovery of the power and prestige possessed by Darth Sidious' Galactic Empire, as well as the restoration of the Imperial monarchy by the Xerxes dynasty after a millennium of Republic rule.

Behind the scenes
The symbol of the Xerxes Imperium was originally designed for Battle of the Sith Lords, a Star Wars video game that was in development at Red Fly Studio until its cancellation on June 24, 2011. On January 7, 2016, concept artwork of the symbol was recycled for use in Star Wars: The Sequel Saga.