EGO DORMIO is the first of the English prose treatises composed by Richard Rolle on the subject of the journey towards spiritual perfection. According to the chronology set out by Nicholas Watson, which divides Rolle's writings into stages based largely on the evidence of self-borrowing throughout his texts, Ego Dormio falls into the category of “late works” in which, along with Melos Amoris, it pre-dates Super Lectiones Mortuorum, Emendatio Vitae, The Commandment, The Form of Living and, in all likelihood, the English Psalter and the shorter vernacular prose pieces. Because it is Rolle's first vernacular prose work of any length, Ego Dormio is of particular interest as the beginning point of his vernacular utterance and his address to a vernacular audience. Throughout this work Rolle relies on both his own Latin works and other writings from the Latin affective tradition to provide the form, theme and content of the text. However, this should not be discounted asmere borrowing and, as the following detailed discussion reveals, Rolle's first vernacular treatise can instead be considered as an illustration of his willingness and ability to adapt, and further develop, his ideas and his method both to a new language and a new audience.