This paper examines the emergence of religious authority in K?fa from the 2nd/8th to the 4th/10th century through a close textual study of three individuals situated at the margins of multiple communal identities, namely Sulaym?n b. Mihr?n al-A‘mash (d. 148/765), Shar?k b. ‘Abd All?h (d. 177/793), and Ibn Barniyya Hibat All?h A?mad b. Mu?ammad b. al-K?tib (fl. 4th/10th century). Each of these men held theological views and issued legal opinions that resisted easy classification. An examination of the earliest and most important biographical works, however, reveals a general consensus as to the designation of each as a “traditionist” (proto-Sunn?) or a “Sh?‘a” (Im?m? or Zayd?). The sources suggest that public expressions of identity outweighed theology as the primary determinant of communal identity. In other words, attendance at particular mosques and participation in public processions to sacred locations were the most critical factors in determining whether a scholar was accepted as a religious (and legal) authority by a given community. This is at odds with modern scholarship which tends to privilege theology over ritual practice in the emergence of sectarian identity. This paper centers on three types of source material: ?ad?th collections, pilgrimage manuals, and biographical dictionaries. The first (i.e. ?ad?th collections) attest to the existence of clearly demarcated K?fan religious communities beginning in the 2nd/8th century. The second (i.e. pilgrimage manuals) depict a fragmented religious geography in K?fa consisting of clearly demarcated “friendly” and “hostile” spaces for the nascent Sh?‘? community. The third (biographical dictionaries) render judgment on the legal authority and reliability of the three individual subjects (see above) through a series of anecdotes about the manner and form of their ritual practice. As a whole, the sources affirm that– while theological views were important – ritual practice was paramount in the construction of religious (and legal) authority.