For most people who study the Andean sacred arts, the answer to the question posed by the title of this post seems fairly obvious. The apus are the sacred mountain spirits that guide, counsel, and protect the people who live within their range of power. However, if you have read my blog posts for any length of time, as you may expect, my answer is going to take us beyond the obvious.
Apu is a Quechua word that means “Lord,” or in some other translations retaining the sacred nuance, it means “Honored One.” More generally, it means chief, mighty one, boss, powerful, rich, and wealthy. It was a title or rank within the Inka royal court and also may have been within the military hierarchy of the Inka Empire. Within the spiritual tradition, we retain the meaning of Lord of a Mountain (for a female mountain spirit, the term usually is Ñust’a, meaning “Princess”). For don Bentio Qoriwaman, an apu is a runa micheq, a shepherd of human beings.
What may come as a surprise to some people is that, as I tell my students, not every mountain is an apu, 
and not every apu is a mountain. Some mountains are just geographical formations: they are not inhabited by a powerful spirit who can guide and protect human beings and communities. And there are other “honored ones” whom we call apus: for example, the seven teqse apukuna, or universal spirit beings: Jesus/the diving masculine principle, Mary/the divine feminine principle, Tayta Inti (Father Sun), Tayta Wayra (Father Wind), Mama Allpa (Mother Earth), Mama Una (Mother Water) and Mama Killa (Mother Moon).
But what of those mountains who are apus? Who exactly is inhabiting them? Who are the “spirit beings” that turn a mundane mountain into an apu? And how did they happen to inhabit a mountain? We don’t know exactly how this transformation happens, but we have clues.
Our first clue is that there is a ceremony, the Wasichakuy, in which upon the death of a master paqo, his apprentices and the local people him (or her) to stay with them in the form of an apu. (Wasi means “house,” “body,” or “temple”; chakuy means “to make.”) In this context, wasichakuy means to make a home or offer a home, and the ceremony involves three generations of a master paqo’s students coming together in ceremony to petition the paqo to take up residence in a local mountain and remain available to them that way. That paqo’s “aya” or soul (aya also means “ghost”) stays on Earth, in the kaypacha, to serve his or her students and the community at large.
Our second clue is that we know this ceremony was actually done for the apu that oversees Wasao, a town about thirty minutes outside of Cuzco. This is the Apu Manuel Pinta. The paqo Manuel Pinta is part of our Cuzco Wachu, or paqo lineage (if you study in the two lineages of don Juan Nuñez del Prado). This paqo lineage goes from don Juan, back through don Benito Qoriwaman and don Melchor Desa, to their teacher don Julian Chhallayku, and to his master don Manuel Pinta. We don’t know the lineage any further back than that (except that its founder was Waskar Inka). Manual Pinta was a real person, a widely respected fourth-level paqo. When he died, his apprentices and the people asked him to stay, and apparently he did, taking up residence in the local mountain, which was renamed for him, Apu Manuel Pinta. That remains its name to this day.
Is there any other evidence of how apus become apus? Well, there is some evidence from a legend, and this legend involves the two highest ranked apus of the region: the suyu apus Ausangate and Salcantay. The legend also explains how another mountain became the Apu Wayka Willka, known through the Spanish Conquistadors as Veronica. (There are at least a half dozen spelling variations of this apu’s name, including Waikawillka, Hunayawillca, and Waynawillca).
The legend goes something like this: At one time Cuzco was experiencing a severe and prolonged drought, and the people were starving. Two brothers, Ausantage and Salcantay, decided to leave Cuzco in search of food to help the people. Austangate went south, to the highlands, where he found great
bounty. He brought back all kinds of food, which helped save the people of Cuzco. Salcantay went north, toward the jungle. In his wanderings, he came to the land of the Anti people, who had a reputation as great warriors. He spent time there, where he met a princess, Waynawillca. They fell in love and were to be married, but the Anti people disapproved. They did not want their princess to marry an outsider and leave their land. So, they banished Salcantay. But he and Waynawillca would not be separated, and they fled together, heading back toward Cuzco.
The Anti warriors followed them, seeking to return with Waynawillca. When they caught up with the two young lovers, there was either a fight during which Waynawillca was killed or they deliberately sacrificed her rather than let this stranger take her from them. The Anti warriors fled back to the jungle.
Salcantay was both grief-stricken and enraged. He returned to the land of the Anti and took his rage out on them in a killing spree, nearly exterminating them. The Gods, seeing all this bloodshed, were not happy, and they decided to turn Salcantay into a mountain so that he could not wreak any more havoc. (Interestingly, “salka” is a quechua word that means many things, among them wild, free, invincible, uncivilized, and undomesticated, and it also can refer, in the sacred work, to the human condition: to our lower nature, to our survival or animalistic impulses, which we seek to “tame” and refine to higher levels of expression.)
That’s where the legend ends, at least in the versions I have found of it. But this version is enough to verify for us that an apu is a mountain enlivened by the spirit of a human being. We can surmise, and certainly imagine, that Ausangate, the savior of the people of Cuzco, was also turned into an Apu, an Honored One. And, as the companion to Salcantay, that the princess Waynawillca was as well.
This hypothesis, if borne out, allows us to see the apus through new eyes. They are not ambiguous nature spirits, but the souls of past paqos and others who contributed to the good of the local people. (Salcantay might be the exception, turned into an apu because of his bad behavior.) When we develop a “relationship” with an apu, we are in a very real sense developing a sacred but “human” relationship. That has been my experience with the Q’ero paqos. They admire, respect, and honor their tutelary apus, and they feel a personal bond with them. In most cases, the apus are their friends. The master paqo whose soul inhabits the mountain is, as the Andean paqos and we recognize, more developed than we are, which is why that apu can serve as a guide and mentor to us. But overall, at least for me, the apus become less about being mysterious nature spirits and become more understandable and approachable.
One last piece of possible evidence about an apu being the “home” for a paqo’s soul: just like a human being, each apu has its own characteristics and gifts. For instance, when we offer a haywarisqa (despacho) to an apu to request something, according to my teacher don Juan Nuñez del Prado, we would direct the 
offering to a specific apu who has it within his or her power to respond in ayni to that request. We wouldn’t offer a haywarisqa requesting help with our health to an apu whose specialty is improving family relationships. There is disagreement among paqos and the local people about the specialties of each apu. For example, some people say that Salcantay is the apu to call upon for healing requests, whereas others say that he is more about helping increase freedom and with the loosening of something stuck or blocked within; still others associated Salcantay with an untamed feminine energy or with more generalized unformed, wild, and even chaotic states of energy. The general point, however, is that, according to don Juan, if we have a specific request in our haywarisqa and don’t know which apu can answer that request, then we should direct that offering not to an apu at all but to Taytanchis, or the metaphysical God. To make our request to someone, in this case an apu, who can’t fulfill it is unproductive to say the least! But in our exploration of how an apu becomes an apu, it makes sense that if individual paqos when they are alive have specialties and particular personal skills and gifts, so would the apu they have become.
Not all apus may have been created this way, and not all apus who were created this way retained the name of the paqos who reside within them. Still, for me, and I hope for you, it’s both a delight and a comfort to know that the greatest paqos and others who were deserving, such as Ausangate, whose munay (feelings/love) and atiy (initiative) saved the people of Cuzco, live on in the kaypacha and are available to us in the form of apus.
Q'enti Wasi - House of the Hummingbird 