Following a lead from Raymond Williams, who talks about how the notion of the generation in its modern sense developed in the late eighteenth century, this paper develops both a conjecture about the social situation in which the notion of the generation became more prominent and a reading of Mary Shelley’s Frankenstein which argues that the novel bears the strong impress of the notion of bonds created between age-mates. While the notion of generation has long been recognized in relation to individual lives and has figured prominently in genealogical accounts of fathers and sons, mothers and daughters, the paper track the way the notion developed expansiveness and publicness — so that persons increasingly came to think of themselves as bound together not because they were members of the same family but rather because they were members of the same generation. The essay examines some of the social structures that contributed to this development and one of its consequences -- namely, a sense of solidarity among persons of the same age who might be otherwise strangers to one another -- useful for thinking about the exclusion of Frankenstein’s Creature.