534 Olaf I Trygvesson
these offices in churches or monasteries, especially at
evening vespers.
The rhythm and ordering of the office were devised
on what might be possible for a community to carry out.
Any decision on that was ultimately a bishop’s. The
whole office did not have to be celebrated. Carolingian
reforms made the office of clerics and monks exactly the
same in frequency and solemnity. They also insisted on
the obligation of each cleric to take part in any office cel-
ebrated in his church. As the public recitation of the
office became too long to be practical, clerics were
allowed to recite it privately. For monks, the divine office
had been the most important aspects of the prayer life as
far back as the time of Saint BENEDICTin the sixth cen-
tury. It was done to promote contemplation and a life of
continual prayer.
See alsoLITURGICAL BOOKS.
Further reading: Andrew Hughes, Medieval
Manuscripts for Mass and Office: A Guide to Their Organi-
zation and Terminology(Toronto: University of Toronto
Press, 1982); Sally Elizabeth Roper, Medieval English
Benedictine Liturgy: Studies in the Formation, Structure, and
Content of the Monastic Votive Office, c. 950–1540(New
York: Garland, 1993); Robert F. Taft, The Liturgy of the
Hours in East and West: The Origins of the Divine Office
and Its Meaning for Today(Collegeville, Minn.: Liturgical
Press, 1986).
Olaf I Trygvesson (Óláfr)(ca. 968–1000) king of
Norway
Olaf was born after the murder of his father, Trygve in
about 968. Legend has it that he grew up among the Rus ́
and became a mercenary. In 991 he entered the service of
the Danish king, Svein I Forkbeard (r. 986–1014), and
participated in attacks on ENGLAND. After returning to
NORWAY, he took the throne on the death of Haakon the
Great (r. 968–995) and reigned from 995 to 1000. He
was one of the great Christianizers of Norway and west-
ern Scandinavia, including ICELAND, the Orkney Islands,
and GREENLAND. In hagiographical traditions, he was the
model VIKING. As king (r. 1015–30), he tried to unite his
kingdom through a common religion. His mysterious
origins and his odd disappearance during a battle
increased the legendary aspects of his life. A biographer,
the Icelander SNORRISTURLUSON, was well aware of its
mythological aspect in 1220. He died in battle on
September 9, 1000.
Further reading:The Saga of King Olaf Tryggwason
Who Reigned over Norway A.D. 995 to A.D. 1000(London:
D. Nutt, 1895); Gwyn Jones, The Legendary History of
Olaf Tryggvason: The Twenty-Second W. P. Ker Memorial
Lecture, Delivered in the University of Glasgow, 6th March
1968 (Glasgow: Jackson, 1968).
Old English SeeANGLO-SAXONS.
Oleg (Helgi)(r. ca. 879–913)legendary Viking prince
of Kiev
Oleg followed his probable kinsman, the Scandinavian
chieftain RURIK, to NOVGOROD, where Rurik took power.
At Rurik’s death, he took over Novgorod, but in 882 he
left and conquered Smolensk and KIEV. He then estab-
lished a new capital at Kiev. Oleg united the SLAVtribes of
the Dnieper Valley and after a number of victories over
the KHAZARSfounded an important Russian principality,
which stretched from Kiev to Novgorod. In 907, he led an
expedition against CONSTANTINOPLE. He failed to capture
the city but forced the BYZANTINESto sign a favorable
treaty on commerce. He died about 912 or 913, from the
bite of a snake, according to a legend.
Further reading:Samuel H. Cross, ed. and trans.,
The Russian Primary Chronicle: Laurentian Text (Cam-
bridge, Mass.: Mediaeval Academy of America, 1953);
Simon Franklin and Jonathan Shepard, The Emergence of
Rus ́, 750–1200(New York: Longman, 1996).olives SeeAGRICULTURE; FOOD, DRINK, AND NUTRITION.Olivi, Peter John (1247/1248–1298)leader of the Spir-
itual Franciscans
Peter John Olivi was born in southern France near
Béziers and entered the FRANCISCAN ORDERat age 12. He
studied THEOLOGYat PARIS, and perhaps at OXFORD,
and was a pupil of BONAVENTURE, who greatly influ-
enced him. He never obtained the title of master. He
taught theology in several Provençal schools of the
Franciscans. He especially defended what he considered
absolutely essential to the Franciscan vocation, the
strict observance of fully voluntary POVERTY. In 1279 he
was consulted on the drafting of a papal bull in which
Pope Nicholas III (r. 1277–80) granted the order new
privileges and confirmed the evangelical character of the
Franciscan Rule, recognizing moderation in its contact
with the material world for the Franciscans and only for
the necessities of life.
In 1282 some Parisian masters of theology con-
demned propositions in his commentary on the SEN-
TENCESof PETERLOMBARD. The next year Olivi agreed to
retract them. From 1287 to 1289 he taught theology at
the convent of Santa Croce in FLORENCEwith DANTEin
the audience. Returning to PROVENCEand continuing
work as theologian and preacher, he exercised a growing
influence on his order, and among a LAITYbecoming
more receptive to his ideas about the necessity of clerical
poverty.IDEAS AND WORKS
He wrote numerous small treatises about attaining a per-
fect love of GOD. This could only be achieved by living in
absolute poverty and detachment from the goods of this
world. Peter saw in a revived Franciscan order the most