The word martyr means "witness", the first centuries of the Church were spattered red with the heroic blood of the martyrs, but when peace came to the Church there was still a need for heroic witness very soon the concept of "white" martyrdom developed.
This was a martyrdom without blood, without violent hatred of the faith. This white martyrdom consisted in a total offering to God a "dying" to self, to the world and its allurements. The age of martyrs melts into the age the early monks and hermits.
At the heart of it was was an interior war, the frontline was chaste celibacy united to an ardent desire to bend one's will to Christ's will. Saint Anthony of Egypt was the great exemplar of this new ascetic way. His twenty years of solitude in the tomb, fighting with his inner demons, was an invitation for many to follow him.
The word "monk" comes from "monachus" meaning alone. Denial of self and the gradual bending of one's mind by continuous prayer, were the tools of sanctification, yes, first celibacy and solitude, but also fasting and nights of sleeplessness. In Egypt especially, gradually these monks gathered together around an Abbas, a spiritual father, and little by little community life developed.
In and around the great melting-pot that was Alexandria especially, there seems to have been an interplay with other great religions. In outward appearance there seems to be little difference between the Christian monk and Hindu sadu, or Buddhist ascetic, both of these traditions were present in the city.
Here is a site of some of the sayings of the Desert Father, they are short and pithy as befits, the silent men of the desert