The Blood-Kin are non-Orcish members of the Orc Strongholds.

The Dragonborn can become Blood-kin by completing an assortment of tasks or by completing the quest, "The Forgemaster's Fingers". If the Dragonborn asked for this title before doing any quests, the reply would be 'Trust like that is not freely given'.

Alternatively, the Dragonborn may complete a quest for certain Orc NPCs. Once their favor has been gained, they will send word out to all the strongholds that the Dragonborn is to be trusted. After completing any of the following quests, the Dragonborn will be granted access to all the Orc Strongholds in Skyrim.