Gerald of Wales 289entries on cosmography and GEOGRAPHY, roughly sum-
ming up the classical achievements and interpretations.
Major accomplishments of the Ethymologiae were both
the dissemination of geographical knowledge throughout
the Middle Ages and the model style of geographical
study and knowledge that prevailed in the West until the
13th century. Christian geographers of the Middle Ages
had a concept of the Earth as a plate with an axis running
through the Mediterranean with a central point at
JERUSALEM. These ideas persisted, as the medieval per-
spective of the world was compatible with FAITH.
DESCRIPTIVE GEOGRAPHYA Ptolemaic tradition was preserved among eastern
Christians living in IRAN and SYRIA. These scholars
divided the world into seven climatic regions, developing
climatology as part of geography. Their conclusions also
led to the development of a popular theory that led to the
concept of a north-south axis of a spherical Earth. Such
ideas about geography were inherited by ISLAMand the
ARABS.CALIPH AL-MAMUN (r. 813–833) tried to have
astronomical tables and geographical maps with accurate
measurements drawn. Arabic and Persian geography
developed further on the basis of accurate and careful
travelers’ descriptions loaded with physical and demo-
graphic data. At the same time contemporary Christian
travelers were only interested in describing holy places
and religious sanctuaries, perhaps in an attempt to make
the biblical past and places more real. In this context
there was little reflection about the changes that had
intervened between biblical times and their own.
ASTRONOMICAL GEOGRAPHYBesides this descriptive geography, the Muslims devel-
oped an astronomical geography. AL-IDRISIwas in the
employ of King ROGERII of Sicily and was a pioneer in
this kind of study with work appearing from 1154.
Under the impact of the translated works of al-Idrisi,
geography gradually became more of a science in Chris-
tendom from the end of the 12th century that included
ideas about a global form for the Earth. A systematic
study of astronomy and NATUREresulted from the impact
of SCHOLASTICISMand the revival of ARISTOTELIANISM.
Roger BACONand others defended the idea of a global
Earth. By the end of the 13th century, perspectives
gleaned from astronomic geography provided the basics
for drawing maps that analyzed the various components
of the Earth. Its achievements were of prime importance
for NAVIGATIONand prepared the tools for geographical
discoveries.
See alsoANTIPODES; GOG AND MAGOG;HENRY“THE
NAVIGATOR”; NAVIGATION.
Further reading:S. M. Ziauddin Alavi, Geography in
the Middle Ages(Delhi: Sterling, 1966); Evelyn Edson,
Mapping Time and Space: How Medieval Mapmakers
Viewed Their World(Toronto: University of Toronto Press,
1997); Frank Lestringant, Mapping the Renaissance World:
The Geographical Imagination in the Age of Discovery,
trans. David Fausett (Berkeley: University of California
Press, 1994).geometry SeeSEVEN LIBERAL ARTS.George of Trebizond (Georgios Trapezountios) (1395–
ca. 1475) humanist, translator of Greek texts into Latin
George’s parents were from Trebizond, but he was born at
Candia in CRETE in 1395. He converted to Western
Catholicism and migrated in 1415 to VENICE, where he
taught Greek and learned LATIN. Employed by Pope
Nicholas V (r. 1447–55), he became part of a papal and
philological academy, headed by Cardinal BESSARION,
which specialized in translating Greek works into Latin.
George translated some 11 major Greek texts, most never
translated, and texts from authors, such as Ptolemy; ARIS-
TOTLE;PLATO, of whom he disapproved strongly; and the
Greek fathers of the church. He authored a treatise on
LOGICand one on RHETORIC, that became a standard for
Italian humanists. He asserted the superiority of the ideas
of Aristotle over those of Plato, criticizing in particular
BESSARION, Plethon (ca. 1360–1452), and Theodore
GAZA. He supported the papacy and views of the Western
Churches at the Council of FERRARA-FLORENCEand was
an ambassador of Pope Paul II (r. 1464–71) to Sultan
MEHMEDII. He died between 1475 and 1486.
See alsoFILELFO,FRANCESCO.
Further reading:George of Trebizond, Collectanea
Trapezuntiana: Texts, Documents, and Bibliographies of
George of Trebizond, ed. John Monfasani (Binghamton:
Medieval and Renaissance Texts and Studies in Conjunc-
tion with the Renaissance Society of America, 1984).Gerald of Wales (Giraldus Cambrensis, the Welsh-
man, Gerald de Barri)(1146–1223) bishop, writer
Born in 1146 the son of an English lord and a Welsh
noblewoman, Gerald of Wales, or Giraldus Cambrensis,
went to school at Gloucester Abbey and then the Uni-
versity of PARIS, where he was a pupil of Peter Comestor
(d. 1179). A master of arts, he also studied canon LAW
in Paris. He served as a royal clerk from 1183 to 1208
and the archdeacon of Saint David’s between 1175 and
1203 As a canon of Hereford, he was twice elected
bishop of Saint David’s, in 1176 and 1199, but was
never consecrated. He wished to obtain the see and turn
it into a Welsh metropolitan archbishopric, but the
English CLERGYblocked his appointment with opposi-
tion to his elevation at the papal curia. Besides preach-
ing the Crusade and writing one of the first medieval
autobiographies, he left important descriptive, moraliz-
ing, and topographical descriptions of IRELAND and
WALES, several saints’ lives, a handbook of conduct for