Note: X and Y are coordinates (light years on XY plane) relative to Terra at (0, 0)
Weisau neighbouring systems
|Star names||2 (Orpheus, Eurydice)|
|Spectral class||F5V & F7V|
|Planets||9, plus asteroid field|
Weisau was described in very great detail including much planetographical data such as geology, topography, and atmosphere as well as socological data in a "Worldbook" entry in the now apocryphal BattleTechnology magazine (Issue #0101). According to this entry, the Weisau system is a close binary system of the suns Orpheus and Eurydice, and features nine planets plus an asteroid field. Discovered in 2235, it was only settled in 2640 for mining purposes.
Only the fifth planet in the system is even marginally habitable, and has been nicknamed "Brimstone" by the natives (though its official name remains Weisau); it has a large satellite or twin world called Fire. Its surface gravity is 1.175g. The temperature range at the polar capital of Port Erebus is given as +10°C on a winter night through +66°C on a summer day while equatorial temperatures can exceed 125°C.
- 2319 - Independent world 
- 2571 - Outworlds Alliance 
- 2581 - Outworlds Alliance (occupied by SLDF forces from August) 
- 2585 - Draconis Combine 
- 2750 - Draconis Combine 
- 2764 - Draconis Combine 
- 2765 - Draconis Combine 
- 2767 - Draconis Combine 
- 2822 - Draconis Combine 
- 2864 - Draconis Combine 
- 3025 - Draconis Combine 
- 3030 - Draconis Combine 
- 3040 - Draconis Combine 
- 3050 - Draconis Combine 
- 3052 - Draconis Combine 
- 3054 - Draconis Combine 
- 3057 - Draconis Combine 
- 3059 - Draconis Combine 
- 3063 - Draconis Combine 
- 3067 - Draconis Combine 
- 3069 - Clan Snow Raven 
- 3075 - Outworlds Alliance 
- 3079 - Outworlds Alliance 
- 3081 - Outworlds Alliance 
- 3085 - Raven Alliance 
- 3130 - Draconis Combine 
- 3135 - Draconis Combine 
- 3145 - Draconis Combine 
Possessed of a hostile and particularly stormy atmosphere, Weisau was a mining world and originally a part of the Outworlds Alliance up until it was occupied by Star League forces and subsequently annexed by the Draconis Combine during the Reunification War.
Targeted during the first wave of attacks, with two brigades from the Fifteenth Division of V Corps - the Forty-third and the Forty-fifth Brigades - landing on the 2nd of August 2581, a few weeks after the opening attacks on Groveld III and Bryceland. The commander of the invasion force, Lieutenant General Clay Strombergs, knew that Weisau was dependent on regular imports of food from other worlds, and his landings concentrated on four large targets, each of which was a transportation hub and spaceport, and each of which was targeted by a company of BattleMechs and two companies of infantry. Although the violent atmosphere of Weisau scattered troops widely, enough were on target or close enough to their targets for all four objectives to be seized within half an hour, with the remainder of the Star League forces landing soon after and taking control of the surrounding communities and facilities.
Although Weisau was notionally defended by a handful of armor companies and a few hundred infantry, this was far from the total extent of the opposition the Fifteenth Division forces would face; Weisau was populated by literally tens of thousands of miners spread across a hundred different locations and employed by mining concerns of varying sizes, and the majority of these miners were more than willing to defend their claims against the invaders using the tools of their trade: heavy vehicles, tools and copious quantities of explosives. Strombergs knew that time was on his side, and that clearing the extensive strip mines and mining sites on Weisau would be difficult compared to severing the planetary supply lines and simply starving the defenders out.
With all of the initial objectives secure, Strombergs had choked off the supply of food and supplies to Weisau; he positioned his forces ready to respond to any hold-outs, while promising amnesty to any who laid down their weapons. The first two weeks saw a number of small mining concerns capitulate, but it wasn't until the Weisau-Gorbbels Mining Cooperative agreed to Star League oversight in early September in exchange for a lucrative contract that active violence erupted on Weisau. Weisau-Gorbbels was one of the largest groups operating on Weisau, and dozens of other mining concerns began scrambling to obtain similar deals... while just as many mining concerns launched attacks against both the SLDF forces and those attempting to submit to Star League control.
Strombergs was forced to use his troops to respond to the attacks, but the combination of severe weather and the difficulty of identifying friend from foe resulted in chaos - which other large, well-organized groups used as cover to launch more raids and secure supplies to allow them to continue to hold out against the Star League forces.
The major resistance on Weisau finally ended in October 2581; by the beginning of October, more than thirty assorted communities and mining concerns were actively resisting, but more than seventy were under Star League control and dozens more had been either abandoned or destroyed in the fighting. Stromberg launched major attacks against three of the most resilient opponents on the 8th of October, each intended to completely destroy the opposition; these attacks were ultimately successful, and by the 10th of October the Star League forces had defeated all three. Of the three major engagements, those at Gorch Canyon and DiSalvo mines were the most destructive, the sites littered with bodies and destroyed equipment as a result of the ferocity of the fighting on both sides, but the Star League forces had a supply chain that would allow them to rebuild these losses. Despite defeating the three most significant opponents, Stromberg's troops would be forced to fight another 17 significant battles before the last organized resistance was defeated.
Although the planet was declared to have been pacified on the 17th of November 2581, the last hold-outs managed to resist until the end of the year. The losses inflicted on the Star League forces were only moderate, but the Star League regiments required several weeks to repair all of the damage inflicted on their equipment by the citizens of Weisau.
On the 25th of July 2585 the Treaty of Cerberus was signed, declaring peace between those involved in the conquest of the Outworlds Alliance, and when the treaty took effect on the 1st of August Weisau and 13 other planets were formally ceded to the Draconis Combine as a part of the treaty terms.
- DiSalvo Mines: site of a major battle during the Reunification War.
- Gorch Canyon: site of a major battle during the Reunification War.
- Weisau-Gorbbels Mining Cooperative
Weisau is misspelled as "Wiesau" in the deployment tables on page 141 of Historical: Reunification War.
| Systems within 60 light-years (distance in light years)|
Closest systems first:
- BattleTechnology, Issue #0101, pp. 6-7 ("Worldbook" entry)
- Era Report: 3145, p. 39, "Inner Sphere -  Map"
- Field Manual: 3145, p. VI, "Inner Sphere -  Map"
- Handbook: Major Periphery States, p. 147, "Outworlds Alliance after Age of War (2571) and at the Fall of the Star League (2750)"
- Handbook: House Kurita, p. 18, "Draconis Combine Founding" -  Map
- Handbook: House Kurita, p. 31, "Draconis Combine after Age of War -  Map"
- Handbook: House Davion, p. 48, "Federated Suns After Age of War -  Map"
- Historical: Reunification War, p. 113, "Weisau"
- Historical: Reunification War, p. 126, "Year Five: Peace In Our Time"
- Era Report: 2750, p. 37, "Inner Sphere -  Map"
- Field Manual: SLDF, p. vii, "Inner Sphere -  Map"
- Historical: Liberation of Terra Volume 1, p. 11, "Inner Sphere -  "
- Field Report 2765: Periphery, p. 36, "Outworlds Alliance Militia Deployment Map - "
- Fiel Report 2765: Draconis Combine, p. 25, "Draconis Combine Mustered Soldiery Deployment Map - "
- Historical: Liberation of Terra, p. 98, "Outworlds Alliance - ] Map
- Handbook: House Kurita, p. 43, "Draconis Combine after First Succession War -  Map"
- Handbook: House Davion, p. 54, "Federated Suns after First Succession War -  Map"
- Historical: Liberation of Terra Volume 2, p. 122, "Inner Sphere -  Map"
- Handbook: House Kurita, p. 53, "Draconis Combine after Second Succession War -  Map"
- Handbook: House Davion, p. 60, "Federated Suns After Second Succession War -  Map"
- House Kurita (The Draconis Combine), p. vii, "Draconis Combine Map - "
- Handbook: House Kurita, p. 64, "Draconis Combine after Third Succession War - 3025"
- Handbook: House Davion, p. 70, "Federated Suns After Third Succession War -  Map"
- Handbook: House Kurita, p. 66, "Draconis Combine after Fourth Succession War -  Map"
- Handbook: House Davion, p. 72, "Federated Suns after Fourth Succession War "
- Historical: War of 3039, p. 133, "Inner Sphere -  Map"
- Handbook: House Kurita, p. 68, "Draconis Combine after War of 3039 -  Map"
- Hanbook: House Davion, p. 76, "Federated Suns after War of 3039 -  Map"
- Era Report: 3052, p. 11, "Inner Sphere -  Map"
- Era Report: 3052, p. 23, "Inner Sphere -  Map"
- Handbook: House Kurita, p. 71, "Draconis Combine after Operation REVIVAL - 3052"
- Objective Raids, p. 24, "Draconis Combien Map"
- Era Report: 3062, p. 11, "Inner Sphere -  Map"
- The Periphery, 2nd Edition, p. 110, "Outworlds Alliance"
- Era Report: 3062, p. 29, "Inner Sphere -  Map"
- Inner Sphere, p. 33, "Federated Suns Map"
- Handbook: House Kurita, p. 74, "Draconis Combine after FedCom Civil War -  Map"
- Handbook: House Davion, p. 82, "Federated Suns after FedCom Civil War -  Map"
- Handbook: Major Periphery States, p. 150, "Outworlds Alliance (3067)
- Jihad: Final Reckoning, p. 43, "Inner Sphere -  Map"
- Jihad: Final Reckoning, p. 47, "The Jihad In Review"
- Jihad Secrets: The Blake Documents, p. 64, "Inner Sphere -  Map"
- Field Report: Clans, p. 28, "Clan Snow Raven & Outworlds Alliance Deployment Map - [August 3079]"
- Field Report: DCMS, p. 21, "Draconis Combine Mustered Soldier Deployment Map - [August 3079]"
- Jihad: Final Reckoning, p. 63, "Inner Sphere -  Map"
- Field Manual: 3085, p. vii, "Inner Sphere -  Map"
- Map of the Inner Sphere 3130
- Era Report: 3145, p. 11, "Inner Sphere -  Map"
- Historical: Reunification War, p. 141, "Outworlds Alliance Front"
- Historical: Reunification War, p. 114, "Weisau"
- Field Manual: 3085, p. 128, "Deployment Table - 3085"
- Era Report: 2750
- Era Report: 3052
- Era Report: 3062
- Era Report: 3145
- Field Manual: 3085
- Field Manual: 3145
- Field Manual: SLDF
- Field Report 2765: Draconis Combine
- Field Report 2765: Periphery
- Field Report: DCMS
- Field Report: Clans
- Handbook: House Davion
- Handbook: House Kurita
- Handbook: Major Periphery States
- Historical: Liberation of Terra Volume 1
- Historical: Liberation of Terra Volume 2
- Historical: Reunification War
- Historical: War of 3039
- House Kurita (The Draconis Combine)
- Inner Sphere (sourcebook)
- Jihad: Final Reckoning
- Jihad Secrets: The Blake Documents
- Map of the Inner Sphere 3130
- Objective Raids
- The Periphery, 2nd Edition