Operation: FORTRESS SIEGE

Operation: FORTRESS SIEGE, also known as the Recapture of the Epsilon Eridani system, was the last major operation conducted by the United Nations Space Command during the Human-Covenant War. UNSC High Command and members of the Concord of Reconciliation met to plan the retaking of the Epsilon Eridani system in January of 2553, following the end of the Battle for Earth.

Background
Following the end of the Battle for Earth in December of 2552, the UNSC High Command would announce preparations for the immediate recapture of the Epsilon Eridani System, in a mission that would be jointly organized with the Concord of Reconciliation led by Arbiter Thel 'Vadam. This was as much done out of patriotism and politics, as it was done out of necessity. While a tactical victory in what was once humanity's most populous system outside of Sol itself would prove that the UNSC-Sangheili alliance was strong enough to deter the disorganized fleets of the former Covenant hegemony, and beat off the most immediate threats to Sol's survival. While a tactical victory would nevertheless provide a second massive morale boost after the Battle of the Ark, there were more pragmatic reasons for focusing on Epsilon Eridani. Firstly, the system itself was strategically important because seven other sliplanes connected to stars that did or currently host a human colony, with its occupation extending slipspace transit times by up to 90 days. Capturing the system was vital for the UNSC's ability to deter ex-Covenant raiders in the Inner Colonies, and act as a junction for not only where the liberation of the rest of human space can be conducted, but also the resettlement of. Secondly, while Reach was glassed beyond repair and space stations had been utterly annihilated, the other planets - Circumstance, Tantalus, and to a lesser extent Tribute - did not suffer as heavy attacks. Some of their planetary infrastructure was still intact enough to be reused or at least recycled, which would allow the UEG to offload the vast numbers of refugees they accumulated during the war. Some of these intact facilities also contained sensitive communiques and research prior to their abandoning, which CONI Admiral Parangosky believed could be repurposed by their occupiers and used against the UNSC.

Meanwhile, the Covenant had not been sitting idly by. Following the system's capture, their military command had authorized the construction of several large naval bases and shipyards, intended to support invasion ships assigned to mop up Earth and the surviving Inner Colonies. Their existence was discovered by ONI's Prowler Corps in December 2552, but the scale was revealed to the UNSC by Thel 'Vadam. Most of the facilities were still under construction, which meant that the UNSC was pressed to attack as soon as possible.

Order of Battle
UNSC
 * 84th Marine Expeditionary Brigade (Special Operations Force)
 * Force Combat Element: 44th Shock Troops Regiment (Reinforced)
 * Aviation Combat Element: 73rd Marine Aircraft Group (Reinforced)
 * Support Combat Element: 28th Combat Logistics Regiment (Reinforced)