This volume contains writings of Mark the Monk, an ascetic writer of the mid-thirteenth century, none of which have hitherto been edited. Mark, a prolific writer, was the spiritual advisor of Irene, sister of Michael VIII Palaiologos (1224-1282). After her husband's death (in the 1250s) she entered a convent and took the monastic name of Eulogia. Mark wrote ever bigger treatises for her edification: first a simple 'Logos', then a concise florilegium, and in the end a huge one citing entire books. The first two of these are critically edited here. Furthermore, the edition contains another sermon similar to the Logos for Irene, but written for a layman. Interestingly, Mark acknowledges very few difference between the lifestyles of monastics and the laity. A small typikon for nuns completes the edition. The few facts about Mark's life known to us stem from a letter to Irene and a general epilogue in the main manuscript, both of which are also edited in this volume. The texts here presented shed light on the ascetic life of the thirteenth century and teach us more about the Palaeologians' relationship to the Church. The main interest of these texts lies in the history of Hesychasm and monasticism, but they also furnish information on the transmission of Patristic texts, of which they often contain interesting variae lectiones. Languages: Greek, English.