Bloodlines is an enormously powerful upgrade for those civilizations lucky enough to have it. Considering its negligible cost, researching it is a top priority for every player who uses at least one type of mounted unit.
Several civilizations have also either bonuses or unique technologies that give additional hit points to certain mounted units. Despite lacking access to Bloodlines, the Franks still have the most powerful Paladin in the game with 192 hit points (with the potential exception of the Lithuanian Paladin). The Mongol Hussar and Elite Steppe Lancer have access to Bloodlines and a bonus that gives +30% hit points; as a result, they have both units with the highest hit points (118 and 124 HP respectively). The Saracen Heavy Camel Rider has access to Bloodlines and Zealotry, which increases the hit points of their Camel units by +20; as a result, they have the Heavy Camel Rider with the highest hit points (170 HP). The Turk Heavy Cavalry Archer, Elite Genitour and Elite Kipchak (the latter two if the player has a Berber and/or Cuman ally) have Sipahi, which provides +20 hit points to them; as a result, they have the Heavy Cavalry Archer, Elite Genitour, and Elite Kipchak with highest hit points (100 HP, 95 HP and 85 HP respectively). The Vietnamese Elite Battle Elephant has access to Bloodlines and Chatras, which gives +50 hit points; as a result, they have the Elite Battle Elephant with the highest hit points (370 HP), as well the land unit with the third-highest hit points.
- A team containing Huns: Researching Bloodlines is 20% faster.
- Japanese: Bloodlines added to their technology tree.
- Spanish: Missionaries are affected by Bloodlines.
- Historically, the Britons are one of the civilizations who best-developed the horse breeding. Ironically, they do not receive the Bloodlines technology. This is most likely for gameplay balance purposes.
- During the Beta, the Vietnamese did not have access to Bloodlines.
- All civilizations introduced in The Last Khans have access to this technology.
- As of Lords of the West, none of the civilizations using the Western European architecture set have access to Bloodlines.
Warriors in the Middle Ages required horses of different types for long movements, scouting, draft animals, and carrying armored knights. Careful breeding of horses allowed the gradual evolution of different horse bloodlines to meet these needs. Civilizations with access to large grasslands were especially adept at breeding horses. In the Middle East and Asia, similar attention was paid to breeding camels for racing speed or for stamina to withstand lengthy marches as part of trade caravans.The Conquerors manual