Kathil Operational Area
History and Description
The Kathil Operational Area - also referred to as the Capellan March Coreward Combat Theater - was a regional command within the Armed Forces of the Federated Suns. One of the subdivisions of the Capellan March, the Kathil Operational Area was a completely military administration, with no civilian governing responsibilities, and was traditionally commanded by a Field Marshal. As an Operational Area the Kathil Operational Area had command authority over a number of smaller regional commands commonly known as Polymorphous Defense Zones or Combat Regions, although during the era of the Federated Commonwealth the PDZs were simply known as Commands.
The size and scope of the Kathil Operational Area expanded and contracted significantly in size after the founding of the Capellan March; at the end of the Age of War in 2571 the Kathil Operational Area consisted of two PDzs comprising just fourteen systems in total. In common with the remainder of the Capellan March the Kathil OA was under the Federated Suns' War Zone Actions from 2787 onwards. The OA consisted of two PDZs during the Star League era, but by the end of the First Succession War in 2821 had expanded to three - the third and most recently-founded PDZ encompassing just five systems. The Chesterton and Demeter system had been isolated from the remainder of the Chesterton Combat Region, with the two systems folded into the Markesan Operational Area by the end of the War. The Kathil OA continued to expand during the Second and Third Succession Wars at the expense of the Capellan Confederation.  The Kathil OA's borders remained stable during the Fourth Succession War and the founding of the Sarna March, and the formation of the secessionist St. Ives Compact left the Kathil OA with the smallest direct border with the Capellan Confederation in its history.
The launch of Operation GUERRERO saw the dissolution of much of the Sarna March and a number of changes within the structure of the Kathil OA, including the incorporation of the remains of the former Sarna and Tikonov PDZs into the Kathil OA, bringing the total size of the OA up to four PDZs. At the end of the FedCom Civil War the Kathil OA was still responsible for four PDZs, incorporating the Achernar, Alcyon, Kathil and Valexa PDzs, although the chaos of the Jihad and the formation of the Republic of the Sphere led to significant changes in the size and borders of the OA. By 3085 the Kathil OA was once again responsible for three PDZs - the Kathil and Valexa PDZs and the Kittery Prefecture. By 3145 the Kathil OA was being actively reduced in size by the aggressive Capellan Confederation Armed Forces invasion of the Federated Suns; whilst still notionally responsible for three PDZs, the Valexa PDZ was under considerable pressure and the Alcyone PDZ had been replaced with the Shoreham PDZ, which consisted of just three systems.
The following sub-regions have all been a part of the Kathil OA at some point during their history:
- Achernar PDZ
- Alcyone PDZ
- Chesterton PDZ
- Kathil PDZ
- Kittery Prefecture
- Shoreham PDZ
- Valexa PDZ
Systems of Note
- Achernar (Achernar PDZ)
- Alcyone (Alcyone PDZ)
- Chesterton (Chesterton PDZ)
- Kittery (Kittery Prefecture)
- Novaya Zemlya (Kathil PDZ)
- Shoreham (Shoreham PDZ)
- Valexa (Valexa PDZ)
Maps of the Operational Area
- Field Manual: Federated Suns, p. 17, "Combat Theater"
- Field Manual: Federated Suns, p. 17, "Polymorphous Defense Zone/Combat Region"
- Handbook: House Davion, p. 125, "Combat Theater/Operation Area"
- Handbook: House Davion, p. 125, "Polymorphous Defense Zone/Combat Region"
- Handbook: House Davion, p. 48, "Federated Suns after Age of War - "
- Handbook: House Davion, p. 125, "Capellan March"
- First Succession War (Source Book), p. 25, "Inner Sphere -  Map"
- Handbook: House Davion, p. 54, "Federated Suns after First Succession War - "
- Handbook: House Davion, p. 60, "Federated Suns after Second Succession War - "
- Handbook: House Davion, p. 70, "Federated Suns after Third Succession War - "
- Handbook: House Davion, p. 72, "Federated Suns after Fourth Succession War -  Map"
- Handbook: House Davion, p. 76, "Federated Suns after War of 3039 -  Map"
- Handbook: House Davion, p. 78, "Federated Suns after Operation Guerrero - "
- Handbook: House Davion, p. 82, "Federated Suns after FedCom Civil War - "
- Field Manual: Updates, p. 137
- Field Manual: 3085, p. Vii, "Inner Sphere - "
- Field Manual: 3085, p. 69, "Armed Forces of the Federated Suns"
- Field Manual: 3145, p. 89, "Armed Forces of the Federated Suns"
- Era Report: 3145, p. 39, "Inner Sphere -  Map"
- Field Manual: 3145, p. VI, "Inner Sphere -  Map"
- Objective Raids, p. 14, "Coreward Combat Theater (Kathil Operations Area)"
- FedCom Civil War (sourcebook), p. 75
- House Davion (The Federated Suns), p. 137, "'Mech Unit Deployment Table"
- First Succession War, p. 23, "Towne"