This article challenges the current consensus dating of the Armenian Lectionary (AL), the earliest record of the feasts and liturgical readings of the church of Jerusalem. For over fifty years, most studies have followed Athanase Renoux in assigning the Greek Vorlagen of AL to the early fifth century c.e., or more precisely, to the years intervening between 417 and 439. This paper highlights severe problems in Renoux’s arguments, however, and produces new evidence supporting a later dating. It concludes that AL reflects the city’s ritual practices in the years following (a) the dedication of Eudocia’s Church of St. Stephen (439), (b) the collapse of the bishop Juvenal’s efforts to integrate the 25 December Christmas feast into the local calendar (after 439), and (c) the construction of Ikelia’s Church of Mary Theotokos (Kathisma) near Bethlehem (c. 456). In turn, through a close comparison of AL’s readings for the 15 August feast “of Mary Theotokos” with homilies by two local preachers—Hesychius and Chrysippus—the paper concludes that the Greek Vorlagen of AL can date no later than 479. In this analysis, AL represents the ritual practices of the Jerusalem church at the beginning of its patriarchal period—that is, after the Councils of Ephesus and Chalcedon, or roughly during the episcopacy of Anastasius I (458–478).