Cambridge University Library, MS Gg.4.27 (hereafter Gg), iconic for its early attempt to collect Chaucer’s works in a single codex, is much more rarely remembered for containing the only “complete” copy of a pair of anonymous macaronic poems usually anthologized as De Amico ad amicam and Responcio. Taking the trilingual lyric diptych as a starting point, this talk considers the significance of this largely Middle English, largely Chaucerian book as a multilingual archive. Thus, my study complicates the conventional understanding of Gg’s place in the formation of a Chaucerian and, in turn, English literary canon. Along the way, I offer revised explanations for some enduring puzzles surrounding the manuscript. For instance, I read Gg’s seemingly arbitrary inclusion of non-Chaucerian works—some of which, including our macaronic poems, rarely appear among the poet’s extensive apocrypha—alongside its distinct orthography or, to borrow Eleanor Hammond’s words, “un-English miswritings.” Such peculiarities point toward a renewed interpretation of the manuscript less as a windfall contribution to the growing authority of Chaucer and the English language in the later medieval period and more as a destabilizing factor in that narrative.