While the joint diaries are the primary source for Michael Field, had they never existed scholarship would still be better served by Bradley and Cooper’s letters than by most other women writers. This chapter explores the family letters as the only contemporary account of Bradley and Cooper’s relationship in the 1880s: Michael Field’s most successful decade. Reading these letters in the context of women’s production of intimacy through correspondence, the chapter considers the tensions in the Cooper household, and the ways in which Bradley and Cooper use their letters performatively to assert a claim for the primacy of their intimate partnership – and the writerly activities entwined in it – as a marriage, over Cooper’s responsibilities as a dutiful, unmarried daughter. This positions the letters as an early experiment with crafting identity as man and wife in practices that would evolve into more complex and audacious revisionings of self in Michael Field.