The Early Christians
n“By the later second century, it was accepted that the celebration of Pascha was a practice of the disciples and an undisputed tradition. The Quartodeciman controversy, the first of several Paschal/Easter controversies, then arose concerning the date on which Pascha should be celebrated. The term "Quartodeciman" refers to the practice of celebrating Pascha or Easter beginning on Nisan 14 of the Hebrew calendar, "the LORD's passover" (Leviticus 23:5).” 

- Easter, from Wikipedia      (http://en.wikipedia.org/wiki/Easter)