The people of the Cordilleras, collectively known by the Spanish as Igorot, were headed by the Apo.
By the 14th century, these polities were organized in strict social classes: The Datu or ruling class, the Maharlika or noblemen, the Timawa or freemen, and the dependent class which is divided into two, the Aliping Namamahay (Serfs) and Aliping Saguiguilid (Slaves).