The Early Christians
n“It is not known how long the Nisan 14 practice continued. But both those who followed the Nisan 14 custom, and those who set Easter to the following Sunday (the Sunday of Unleavened Bread) had in common the custom of consulting their Jewish neighbors to learn when the month of Nisan would fall, and setting their festival accordingly. By the later 3rd century, however, some Christians began to express dissatisfaction with the custom of relying on the Jewish community to determine the date of Easter. The chief complaint was that the Jewish communities sometimes set their week of Unleavened Bread to fall before the spring equinox”

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