This paper examines the ways in which Zaydi and Imami authors of the late medieval and early modern periods appropriated the legacy of a particular subset of early Shi'i hadith narrators as it was transmitted in Sunni literature. In the eighth and ninth centuries, roughly two hundred narrators active in the proto-Sunni milieus that gave rise to the standard Sunni collections of hadith were labeled as Shi'is. These narrators ran the gamut of potential Shi'i affiliations, and while some of them were prominent contributors to Zaydi and Imami literature, for the most part their legacy was preserved and negotiated in Sunni biographical and hadith literature. Between the fifteenth and eighteenth centuries, both Zaydi and Imami authors employed this legacy towards a variety of ecumenical, polemical and apologetic ends. Among Zaydis, discussions of these narrators were inaugurated by Ibn al-Wazir (d.1436), who drew heavily on a hadith-based Sunni traditionalism in an ecumenical project that sought to transcend inherited sectarian boundaries. Ibn al-Wazir argued that Zaydis should benefit from the study of Sunni hadith and that the Sunni treatment of early Shi'i narrators was testimony to the objectivity of their methods. Later Zaydi authors under the Qasimi dynasty built on Ibn al-Wazir’s adoption of Sunni traditionalism, but were unanimous in their rejection of his assertion that Sunnis had treated early Shi'i narrators objectively. They argued that the Sunni tradition in fact displayed entrenched biases towards these narrators and the pro-'Alid material that they transmitted. At the same time, many Zaydis invoked the comments of Sunni hadith scholars on these narrators in order to establish a positive valence for Shi'ism from within the Sunni tradition. Among Imamis, Safavid era scholars beginning with Qadi Nur Allah al-Shushtari (d. 1610) inaugurated a new phase in the reception of these narrators by marshaling a substantial amount of material on them from Sunni sources in biographical works that were designed to demonstrate the substantial and ubiquitous nature of Shi'i contributions to all branches of Islamic learning and culture. Although these authors drew extensively on Sunni biographical literature, unlike the Zaydis, they had no intent of establishing themselves as legitimate participants in the Sunni tradition and they reproduced standard Imami polemics against Sunnism in their works. The trends established in the Imami and Zaydi scholarship of this era continue to shape modern discussions of this subject and have even influenced some pro-'Alid Sunni authors.