After the Blackout, war erupted through all the Inner Sphere. The Draconis Combine and Capellan Confederation were two of the most successful states, as they have grown more than ever, mainly at expense of the Republic of the Sphere and Federated Suns space.
They have different goals, as the Capellan leader, Daoshen Liao was obsessed with the supposed threat he sees in the Republic space, entrenched behind The Walls of Fortress Republic, while the Coordinator of the combine, Yori Kurita was much more interested in conquering Federated Suns space than anything else. However, as they shared common enemies, the Suns and the Republic, Daoshen Liao chose to develop a formal alliance with the Combine. In early April of 3149, an ambassadorial contingent from Capella arrived in Combine space, and was shuttled to Luthien to met with Coordinator Yori Kurita and her advisors. Warlord Toranaga was not permitted into the meetings until very late in the negotiations. Daoshen Liao proposed a military partnership that harkened back to the Concord of Kapteyn. The Free Worlds League wasn't invited to this alliance, but the Unity Pact shared the spirit of cooperation against their common enemy. When Kanrei Toranaga was invited to the talks, he attempted to sway the Coordinator to accept, but fall on deaf ears. Yori feared that the Combine alliance would allow the Capellans to claim Earth and that later, the Chancellor would then declare himself First Lord of the Star League which would trigger a new Succession War. But after Daoshen shared the information than Devlin Stone was alive and well, and was responsible of recent Republic attacks on the Dieron district, the Coordinator, who blamed Stone for the Combine weakening in the last decades, finally agreed to sign the pact. Commencement of joint military operations against the Republic space began with both sides' militaries participating. The Unity Pact was signed on 21 April at Unity Palace. Since that moment, the Combine joined the other interstellar powers striking at the Republic.
Anyway, the Combine's contribution to the Pact was minimal, as they did not want to help the Confederation very much, and they were focused on fighting the Federated Suns. The Combine only launched Operation TIAMAT the same year, taking the Republic worlds of Asta, Altair and Fomalhaut and four more worlds of the Suns, separating them from Republic space. In 3150 they sent the Hikage, one of their newest and better regiments, to assist the Capellans to take Northwind. But the Battle of Northwind (3150) only proved the two allied states didn't work well: the Hikage took a lot of time to help the Capellans, and these units, fearing that the Kuritans were planning to attack them, launched an attack, and both 'Allies' finished fighting each other at the same time they fought the Republic defenders. The destruction of the working HPG, the most valuable asset on the planet, made the Hikage lose interest, and they retreated from the world, and the Capellans made the same soon after. Both blamed each other for the sabotage, but in reality was done by Republic infiltrators. The disaster sounded the death knell of warm relations between the Confederation and Combine.
- The Unity Pact differed from the Concord of Kapteyn because it was much less complete than it: it don't contained provisions for mutual defense, only joint military operations.
- Shattered Fortress, p. 67
- Shattered Fortress, p. 68
- Shattered Fortress, p. 695
- Shattered Fortress, p. 96
- Shattered Fortress, p. 97
- Shattered Fortress, p. 95