Battle of Sigma Octanus IV

Previous:	Massacre of Troy
Next:	Fall of Reach
Battle of Sigma Octanus IV
Conflict:	Human-Covenant War Siege of the Inner Colonies
Date:	July 17–18, 2552
Location:	Sigma Octanus system Sigma Octanus IV
Outcome:	UNSC tactical victory Covenant successfully repelled Covenant strategic victory Forerunner artifact retrieved Locations of Installation 04 and Reach learned
Details Belligerents United Nations Space Command Covenant Commanders Vice Admiral Michael Stanforth General Kits† (presumed) Captain Jacob Keyes Corporal Harland MCPO John-117 Unknown Strength Epsilon Eridani Fleet Battle Group Leviathan 49 vessels 2 carriers Presumably at least 1 Epoch-class heavy carrier 1 Marathon-class heavy cruiser UNSC Leviathan Approximately 14 destroyers UNSC Iroquois (first to be present) UNSC Lancelot Approximately 31 frigates UNSC Gettysburg UNSC Allegiance UNSC Fair Weather 1 Repair and refit station UNSC Cradle At least 1 prowler (did not participate in fleet actions) 12 SPARTAN-IIs Blue Team Red Team Green Team 1,600 Marines 1 Spartan-III Colonial Militia Second Fleet of Solemn Accord 4 vessels (early) 1 carrier 1 stealth ship (deployed after the carrier retreated) 1 Wik-pattern light destroyer 2 frigates 24 vessels (after 0625 hours) 2+ CAS-class assault carriers Sinaris-pattern heavy destroyers Ket-pattern battlecruisers Ceudar-pattern heavy corvettes Legions of ground troops Huragok Mgalekgolo Kig-Yar Unggoy Sangheili Casualties 41 ships destroyed or disabled More than 20 ships lost UNSC Cradle UNSC Fair Weather Nearly 1,000 naval personnel killed Hundreds of naval personnel wounded 1,586 Marines killed General Kits (presumed) Lieutenant McCasky Devesh Bhasin 300,000 civilians killed 1 SPARTAN-II wounded James-005 Presumably all forces on planet surface All forces in Côte d'Azur 19 ships destroyed 3+ ships of the 4-ships Covenant battlegroup, including later the internally docked stealth ship At least 2 CAS-class assault carriers At least 8 Ceudar-pattern heavy corvettes

"We've come to take Sigma Octanus IV back from the Covenant. To do that, we're going to kill every last one of them."

— John-117 to Corporal Harland

The Battle of Sigma Octanus IV was an engagement fought between the United Nations Space Command and the Covenant in mid-2552. Despite taking heavy losses, the UNSC successfully repelled the Covenant force from the Sigma Octanus system, gaining a victory. However, multiple Covenant objectives were achieved, as they succeeded in retrieving a Forerunner artifact leading them to Installation 04, as well as finding out the location of the human stronghold planet Reach.

The battle

Opening actions

Main article: Keyes Loop

On July 17, 2552, Ensign William Lovell logged a large gravitational anomaly inside Slipstream space. Deciding that it could not be any form of