Citadel-class Escort Destroyer

The Citadel-class is an Escort Destroyer in the UNSC Navy. Created to be a long range, highly capable escort vessel, the Citadel fills a niche left open in the aftermath of the Human-Covenant War where many smaller frigates perished easily defending larger ships, the Citadel serves to not only be able to screen and protect the ship its escorting but also itself.

History
Designed between 2548 and 2550, the Citadel-class was built in response to the ongoing, exorbitant losses of existing escort vessels such as frigates and smaller destroyers such as the Stalwart-class and Halberd-class respectively. The class also became one of the first to field the latest in defensive countermeasures supplied by Rancor Corporations. However the ship did borrow from its predecessor, the Halberd-class, with regards to its MAC layout and its focus on heavy armor making the ship more than capable of defending itself.

Production of Block I of the vessel began in 2551 and ran until 2553 during which 20 ships were ordered however the 4 being made at Earth were destroyed during the Battle of Earth with the remaining 16 coming into service in the aftermath during early to mid 2553. However due to the success of the vessel in action against Covenant Remnant groups a second, improved set were ordered featuring thicker armor and compatibility for possible shield generators, this was Block II which was ordered in 2555 and composed 30 ships which were finishing production by the time of the Created Crisis. Block II featured Titanium A3 Armor, new Targeting Systems and the first of Rancor Corporations Magneticised Ferrite Field Generators