Bibliotheca Arnamagnæana - 01.06.1970, Síða 365

Gerlandus as the Source for the
Icelandic Medieval Computus (Rim I).
By Ellen Zirlcle, Cornell University.
When the Icelanders decided to adopt Christianity as the national
religion sometime about the year 1000, they also had to have some
system of reckoning when Easter and the moveable feasts were
to be celebrated each year. That system had to come from Europe,
although in the version that has come down to us it had been
changed and adapted to some degree.
The first scholar to take up this problem of the European source
was Nat. Beckman.1 He found in the Icelandic historical works
written about 12002 a consistent lowering by seven years of the
dates given according to the Incarnation and connected it with
a little known computist of the eleventh-twelfth century, Ger-
landus,3 who had “corrected” the Dionysian era by seven years.
1 “Quellen und Quellenwert der islåndischen Annalen” in Xenia Lideniana:
Festskrift tillagnad Professor Evald Lidén (Stockholm, 1912), p. 30 f.; “Veten-
skapligt liv på Island under 1100- och 1200-talen”, in Maal og Minne VII (1915),
p. 195 f.; Alfrædi islenzk II (København, 1914—16), p. xiv ff.
2 I.e., “jHungrvaka m.fl. Biskupasqgur, det galler åven Sverris saga, kort sagt
hela den historiska litteratur, som framkom vid slutet av 1100-talet.” Maal og Minne
(1915), p. 197. For fuller information see the ar ticle by Jon Johannesson and the
book by 6lafia Einarsdåttir cited below.
3 Gerlandus, as Charles Haskins (Studies in tlie History of Mediaeval Science,
Cambridge, 1924, p. 85) surmised and as L. M. de Rijk (Garlandus Compotista:
Dialectica, Assen, 1959, in the introduction) supported with good evidence, died
before 1102. He was born in Lorraine, became canon late in life at Besan^on and
de Rijk gives some reasons to believe he was present in England in the reign of
Harald I (1036—1040). According to de Rijk Gerlandus died between 1084 and 1102.
The former date is brought into question by a note in the table in Digby 56,
fol. 163v, and in the British Museum Vesp. A IX, fol. 33, whereby Gerlandus saw
an eclipse in the year 1093 of the Dionysian era. In his edition of the works of
Roger Bacon (Opera hactenus inedita Rogeri Baconi, vol. VI, published 1926 in
Oxford, p. xviii) Robert Steele notes only the Vespasianus manuscript.