Terminal.png This article, Io-class light cruiser, was written by DirgeOfCerberus111. Please do not edit this fiction without the writer's permission.
Help.png This article, Io-class light cruiser, is currently under active construction.

Writer share.png This article, Io-class light cruiser, was written by DirgeOfCerberus111, but may be used freely by other users even without the author's explicit permission.
Class overview

Io-class light cruiser


United Nations Space Command

Preceded by
Succeeded by


General characteristics

Light cruiser

Slipspace Drive

Shaw-Fujikawa Translight Engine


1-1.3 meters Titanium-A battleplate


Initial armament

  • Heavy-coil Magnetic Accelerator Cannon (1)
  • Ares missiles (26)
  • Fusion Rockets (2)
  • M101 "Saber" point-defense guns (20)

2525 refit


24 GA-TL1 Longswords

Additional information

Insurrection, Human-Covenant War


The Io-class light cruiser was class of light cruisers used by the UNSC during both the Insurrection and the Human-Covenant War.

The ship was designed as part of the UNSC's military rearmament program along with the Hades-class heavy cruiser. At the time it was considered a top-of-the-line warship armed with a new heavy coil Magnetic Accelerator Cannon and twenty-six archer missile pods. The Io-class was well liked by the Navy who found to be well-suited for patrolling and economically appealing. When the Halcyon-class was introduced the Navy still preferred the Io which for every Halcyon they could build four. They were deployed in great number during the Eridanus II Insurrection where they assisted in combating the Insurrectionist's fleet.

The class was very popular with their crews who found the living conditions aboard them preferable to other ships. The interior was spacious for a naval ship and its simple and straightforward design made maintenance a simple matter. However, it was considered the glass cannon of the fleet having only 1-1.3 meters of Titanium-A armor and lacking much internal bracing.

Even though production ceased in 2512 with the introduction of the Marathon-class the Io-class was still in service by 2525 in reserve fleets and patrolling the Outer Colonies. The Io-class took catastrophic losses in the early years of the Human-Covenant War where their thin armor and light armaments made them easy prey for Covenant plasma weapons. The Admiralty considered decommissioning the Io-class but simply could not afford to scrap an entire line of cruisers given the desperation of their situation. They continued to serve in the war participating and taking heavy losses in the battles of Harvest, Alpha Aurigae, XI Boötis A and numerous other battles until the Io-class was rendered extinct by 2535.

Known Ships of the Line

 Name   Hull Classification Symbol   Commissioned   Notes 
UNSC Io IC-1 January 23, 2490 Lead ship.
UNSC Toulons IC-12 April 3, 2491
UNSC Eclipse IC-13 August 9, 2492
UNSC Millennium IC-200
Community content is available under CC-BY-SA unless otherwise noted.