Bloodlines

Bloodlines is a technology in Age of Empires II: The Conquerors that can be researched at the Stable. It is available in the Feudal Age and gives all Cavalry and Cavalry Archers +20 Hit Points. Bloodlines costs and, and is available to the Chinese, Goths, Huns, Mongols, Persians, Saracens, Spanish, Teutons, Turks, Slavs, Magyars, Italians and Indians.

The Forgotten Changes

 * Japanese get Bloodlines
 * Spanish Missionaries are now affected by Bloodlines.

Tactics
Bloodlines is an enormously powerful upgrade for those civilizations lucky enough to have it. Researching it is a top priority (especially given its negligible cost).

Real info
Bloodlines refers to one's ancestry. In this case it can be presumed to have close ties with the breeding of animals and plants for specific purposes.