He is also called 'Mark the Athenian' because he was born in Athens. When his parents died, he pondered the transience of all earthly things, gave his goods to the poor, and embarked on a plank in the sea, asking God to lead him wherever He desired. By God's providence, Mark was cast up on the shores of Libya, where he settled as a hermit on a mountain called Trache. (Some say it was in Ethiopia, but this seems less likely.) There he lived for ninety-five years, never seeing another human being.

Saint Serapion visited him before his death and recorded his life. Serapion asked Mark if there were any Christians whose faith was so great that they could say to a mountain 'Get up and cast yourself into the sea,' and it would be so. Immediately the mountain on which they stood began to move like a wave, but Mark raised his hand and stilled it.

On his deathbed, St Mark prayed for the salvation of all men and gave up his soul to God. Saint Serapion saw an angel carrying Mark's soul, and a hand extended from heaven to receive it. Saint Mark was about 130 years old when he reposed.