In Paulo Coelho's The Alchemist, who were the Moors who had invaded Spain?
From [the ramp], he could see Africa in the distance. Someone had once told him that it was from there that the Moors had come, to occupy all of Spain.
Later, as the boy studies the city before him and ponders the situation he finds himself in, he mentions the Moors again:
The wind began to pick up. He knew that wind: people called it the levanter, because on it the Moors had come from the Levant at the eastern end of the Mediterranean.
Sources identify the "levanter" as a common sea term in Spain which indicates a wind coming from the east "while at sea."
So the Moors came from the east to infiltrate Spain. However, the term "moor" does not refer to a distinct cultural group. It can include "historic and modern populations of Berbers, Black Africans and Arab descent" coming from the northern part of Africa, arriving in Spain as conquerors. They invaded and settled on the Iberian Peninsula, where they remained for eight hundred years—they were mostly Muslim.
Mainstream scholars observed in 1911 that "The term 'Moors' has no real ethnological value."
There does not seem to be a significant co-relation between Santiago's situation and the choices he must make. Perhaps he feels the wind, associated with the invasion of the Moors, as a sweeping change he feels he is going through, having left his life as a shepherd. Or it may be foreshadowing on the part of Coelho to indicate the way new knowledge and a new understanding will come over his life, much the way the Moors invaded, changing the "landscape" of Santiago's life forever.