Within life-writing studies, the majority of scholars approaches diaries as linear, monological, and spontaneous objects. Such an understanding usually leads to chronological, monographical and truth-seeker interpretation of diary as a genre. On the contrary, varying the scale of observation and the focus allow to appreciate the way diaries are essentially co-written and cross-generated objects. 2PLUMES project will investigate these cross-genesis (genèse croisée) and co-writing (co-écriture) practices as they are carried out in 20th century female diaries read and commented by male readers. By combining approaches drawn from textual genetics, gender studies, and digital humanities, the project will delve into archival research in order to reconceptualize diaries as a “gendered-genre”. The project will take on three co-written diaries (Catherine Pozzi and Paul Valéry; Jean-Paul Sartre and Simone De Beauvoir; Louis Aragon and Elsa Triolet), which will firstly lay the groundwork for an extensive study and the development of a general analysis and editing method. 2PLUMES will be structured around three main goals. Firstly, by combining archival studies and digital humanities, it will analyze the ways in which co-writing and cross-genesis practices are carried out in diary genre; genetic analysis and critical transcription of the corpus’ manuscripts, most of which are held Bibliothèque National de France’s archives, will be at the heart of this goal, and will involve the gradual enrichment of the digitalized archives co-hosted by ITEM. Secondly, by combining textual genetics and literary theory, it will shed light on the processes involved in the textual and conceptual production of female diaries, while tackling head-on the epistemological and gender issues raised by co-writing practices. Finally, drawing on history of the book and every day life studies, the project will extend its field of investigation and explore both the role and the evolution of women’s diaries from 19th century to the contemporary, while opening the corpus to other European traditions.