Controversy surrounded the determination of the date of Easter from the 2d to the 8th century, and is dealt with here as: (1) the quartodeciman, (2) the Roman-Alexandrian, and (3) the Celtic Easter controversies.
Quartodeciman Controversy. The Asiatic practice in the 2d century of observing Easter on the day of the Jewish Passover conflicted with the Roman custom of celebrating Easter on Sunday, the day of the Resurrection. Occasionally, the Quartodecimans celebrated Easter on the day that other Christians were observing Good Friday. Originally both observances were allowed, but gradually it was felt incongruous that Christians should celebrate Easter on a Jewish feast, and unity in celebrating the principal Christian feast was called for. However, an attempt by Pope victor i (189–198) to impose Roman usage proved unsuccessful in the face of a determined opposition led by Polycrates, Bishop of Ephesus. Although Quartodecimanism waned in the 3d century, it survived in some Asiatic Churches as late as the 5th century.
Roman-Alexandrian Controversy. In the beginning Christians depended on Jewish authorities to calculate the date of the Passover, and thus of Easter; but by the 3d century some Christians started to determine Easter independently. Since the date of the Passover (14th of Nisan) depends on a lunar calendar, there was a perennial problem of reconciling the shorter lunar calendar year with the longer solar year of the Julian calendar by the periodic addition of an intercalary month. It was obviously desirable to construct a cyclic arrangement so that Easter, a fixed day in the lunar calendar, would occur according to a predetermined pattern in the Julian calendar. Unfortunately, because of the complexities involved in the calculations, the number of years in the proposed cycles varied from place to place; thus the fixing of the date of Easter varied, affording the basis for a new series of controversies.
In Rome hippolytus devised a 16-year cycle, beginning with the year 222; since its calculations were defective, it was replaced later in the century with an 84-year cycle. In the East anatolius of laodicea (d. c. 282) constructed a calendar with a 19-year cycle, which was adopted at Alexandria. The Council of Arles (314) hoped to achieve uniformity by observing Easter on the same day as the See of Rome, which was charged with announcing the date in advance through circular letters. A similar effort was made in the East at the Council of Nicaea (325). The exact wording of the Nicene decree is uncertain, but it apparently approved the practice of celebrating Easter on the Sunday after both the 14th of Nisan and the vernal equinox, thus implicitly rejecting both Quartodeciman and Jewish calendars (Eusebius, Vita Constantini 3.17–20).
However, no one Easter cycle was universally accepted; rather, different cycles continued to prevail. During the 4th century, this frequently resulted in different dates for Easter (Ambrose, Epist. 23), though on occasion Alexandria accepted the Roman date and vice versa. After repeated efforts by Pope St. leo i (440–461) to achieve uniformity between the divergent cycles of Rome (84 years) and Alexandria (19 years), Victorius of Aquitaine constructed a 532-year cycle under the patronage of Leo's successor, Hilary (461–468). During the Laurentian schism, the cycle of Victorius was followed by the antipope Laurentius; this resulted in the reintroduction of the 84-year cycle by the party of Pope symmachus (498–514).
In the East, the 19-year Anatolian cycle had been computed by Cyril of Alexandria for five cycles (436–531). Some years prior to its expiration, dionysius exiguus, a monk in Rome, constructed an extension (to 626), which basically followed the 19-year cycle. Dionysius, however, decided to date his calendar, not from the era of Diocletian as Cyril had done, but from the birth of Christ. Unfortunately, the calculations of Dionysius in dating the "Christian Era" were inaccurate, but the system still remains in use (a.d. for anno Domini). The acceptance of this cycle in Rome ended Rome's longstanding controversy with Alexandria. Yet it was only in the 8th century that the cycle of Dionysius was universally adopted in Western Europe; according to Gregory of Tours (Hist. Franc. 5.17; 10.23), the cycle of Victorius, retained by a minority, resulted in divergent celebrations of Easter in Gaul during the 6th century.
Celtic Easter Controversy. An 84-year cycle had been introduced into Ireland at the time of its Christianization in the 5th century; subsequently, the Irish monks and missionaries introduced their Celtic calendar in the regions where they settled, thus coming into conflict with Christians who followed other calendars. In Gaul, the monasteries established by St. columban (c. 550–615) followed Celtic usages. This aroused considerable opposition from the Gallic bishops who accused Columban of being a Quartodeciman. Nonetheless, he continued to follow the Celtic practice at his monastery of Luxeuil. Sometime after his death, the Gallic calendar was introduced without any recorded opposition.
The Celtic calendar had been introduced also into England. With the arrival of augustine of canterbury and the Roman missionaries sent by Pope Gregory I (590–604), an attempt to introduce the Roman calendar encountered opposition from the Christians following the Celtic custom. The dispute was carried into the royal family of Northumbria, where King Oswy, following Celtic usage, observed Easter, while Queen Eanfled, according to the Roman calendar, observed Palm Sunday. At an assembly convoked at Whitby (664), King Oswy, after hearing the arguments of St. colman on behalf of the Celtic observance and of wilfrid of york on behalf of the Roman usage, decided in favor of the latter in deference to the authority of St. Peter (Bede, Ecclesiastical History 3.25–26). Subsequently, Theodore of Tarsus (c. 602–690), Archbishop of Canterbury, undertook to extend the Roman calendar throughout England. In Scotland, the Roman usage was introduced by King Naitan in 710; acceptance followed at Iona a few years later (Bede, Eccl. Hist. 5.21–22), and by the 9th century it prevailed in Wales. Uniformity of Easter observance was thus attained in the British Isles.
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