In tKet 4.5 a rare distinction between types of captives is introduced, bearing dramatic consequences: a husband must ransom his wife if she is a "captive of banditry" but not if she is a "captive of a kingdom." In addition, the Tosefta rules that if divorced, the ransomed wife is entitled only to a ketubah of 100 dinars, and not of 200 dinars as expected by the standard halakhah. Despite previous scholarly efforts, the rationale for the distinction and its unique legal implications remains unclear. In this essay, we offer a solution based on the Roman law of captivity. We argue that this distinction is adopted from the Roman law that distinguishes between captors based on the degree of their political legitimization. Furthermore, the reduced monetary obligations of the husband in the Tosefta should be understood in light of the legal consequences of captivity on a citizen which, according to Roman law, entail suspension or dissolution of all the citizen's legal bonds, including marriage. Beyond solving local problems, the essay points to a profound impact of the Roman model of citizenship on tannaitic halakhah. According to the common opinion, external circumstances cannot impact the status of a Jew vis-à-vis the halakhah. In contradistinction, the Tosefta follows the Roman model that views the applicability of the law as a matter of citizenship, which may be lost.