In the era of perpetual allegiance, the nationality regimes of Germany and China were characterised by restricted, instead of voluntary, expatriation. Although this policy reflected the two states' perceptions of overseas Germans and Chinese as sources of national strength, it also resulted in widespread dual nationality practices. Using case studies of Germany and China, this article analyses the right to expatriation in the aforementioned era. This study suggests that both the imperial regimes adopted strict expatriation rules with knowledge of the possibility of dual allegiance but remained indifferent to its consequences. Dual nationality practices were the accidental result of strict expatriation rather than a deliberate outcome.