Dark Elf, Dwarf, High Elf, Grand Cathay, Kislev, Khorne, Nurgle, Ogre Kingdoms, Skaven, Slaanesh, Tzeentch and Vampire Counts factions may confederate with their own kind if mutual relations are good and one is significantly stronger than the other.Beastmen factions are more likely to confederate if one is much stronger than the other, be it at high relationship or as part of a peace deal.Be aware that depending on the balance of the assets you acquire, your income may be adversely affected. If you are strong enough and they accept your offer, their faction will be assimilated into your own their settlements will become yours, as may some of their armies.
Ask the other faction to join your confederation.
