13X was the name of a Victory-class Star Destroyer of the Galactic Empire's Imperial Starfleet which was under the overall command of the self-styled High Admiral Treuten Teradoc some eight years after the Battle of Endor.
After the final death of Palpatine, Teradoc maintained a whole flotilla of Victory-class Star Destroyers under his command, all with their hulls armored with a red-colored alloy, earning them the name Crimson Command. When Admiral Daala attacked Teradoc's forces under the flag of another warlord, Supreme Warlord Harrsk, Crimson Command was under the leadership of then-Vice Admiral Gilad Pellaeon with the 13X as the flotilla's flagship.
When Daala asserted full control from many of the warlords of the Deep Core, Pellaeon was given command of forty-five of the larger Imperial-class Star Destroyers and Crimson Command was given over to Colonel Cronus. From the bridge of the 13X, Cronus successfully conducted a series of attacks and raids throughout the New Republic before rejoining Daala's fleet at Yavin 4.
There, in pitched battle against a New Republic fleet, a damaged Corellian gunship rammed the bridge of the 13X, killing Cronus and annihilating the warship.