only trigonometrical tool used in antiquity, Menelaos’
theorem (al-shakl al-qat.t.a ̄‘), as well as a commentary,
with frequent original digressions, on Ptolemy’s Plani-
sphaerium, which is the fi rst of the studies dedicated by
Andalusian astronomers to the astrolabe: its infl uence
is clear in the thirteen-century Latin compilation on
the instrument ascribed to Messahalla (M ̄a sh ̄a ’all ̄a h, fl.
Bac ra, 762–809) the echoes of which reach the treatises
on the astrolabe written by the collaborators of Alfonso
X and by Geoffrey Chaucer (ca. 1340–1400). He is the
creator of an important school of mathematicians and
astronomers, and two of his disciples (Ah.mad ibn al-
S. aff ̄ar and Ab ̄u -1-Q ̄asim As. bag ibn al-Samh. ) collabo-
rated with him in his revision of the Sindhind zı j ̄ (as-
tronomical handbook with tables) of Al-Khw a rizm ̄ ̄ ı
(fl. 800–847), a work having an Indian pre-Ptolemaic
origin, probably known in Al-Andalus since ca. 850.
This revision, extant in a Latin translation by Adelard
of Bath (fl. 1116–1142), adapted certain tables to the
geographical coordinates of Córdoba, changed the Per-
sian calendar used in the original for the Hijra calendar,
introduced Hispanic and, possibly, Ptolemaic materials
and added a considerable amount of new astrological
tables (about one-fi fth of the extant set of numerical
tables), which improve considerably the techniques used
by Al-Khw ̄arizm ̄ı himself. He also introduced Ptolemaic
astronomy in al-Andalus: he studied the Almagest and
wrote astrological additions for the Ptolemaic z ̄ı j of
Al-Batt ̄an ̄ı (d. 929).
Further Reading
Burnett, C. (ed.) Adelard of Bath: An English Scientist of the
Early Twelfth Century. London, 1987. 87–118.
Mercier, R. Astronomical Tables in the Twelfth Century. London,
1988.
Neugebauer, O. The Astronomical Tables of Al-Khw ̄arizm ̄ı. Trans.
with commentary by H. Suter. Copenhagen, 1962.
Samsó, J. Las Ciencias de los Antiguos en al-Andalus. Madrid,
- 84–98.
Suter, H. Die Astonomischen Tafeln des Muh. ammed ibn M ̄u sa
al-Khw ̄arizm ̄ı in der Bearbeitung des malama ibn Ahmed
al-Madjr ̄ıt. ̄ı und der latein. Uebersetzung des Athelhard von
Bath. Copenhagen, 1914.
Vernet, J., and M. A. Catalá. “Las obras matematicas de Maslama
de Madrid.” In Estudios sobre Historia de la Ciencia Medi-
eval. Ed. J. Vernet. Barcelona, 1979. 241–71.
Julio Samsó
MATILDA, EMPRESS (1102–1167)
The daughter of King Henry I of England and his wife,
Matilda of Scotland, Matilda became the empress by
virtue of her marriage to the Salian emperor, Henry
V. Her father accepted the marriage proposal during
Whitsuntide of 1109, at which time she was only eight
years old. In the spring of 1110 she was sent to Germany
under the care of Bishop Burchard of Cambrai, betrothed
to Henry V at Utrecht, and crowned at Mainz by Arch-
bishop Frederick of Cologne. Henry V then dismissed
all her English attendants, and the child was taken under
the guardianship of Archbishop Bruno of Trier to learn
the German language and customs. The marriage fi nally
took place in January 1114 at Worms, the new consort
now being twelve years old and her husband some thirty
years her elder. Henry V had used the years between the
betrothal and marriage to spend Matilda’s enormous
dowry of ten thousand silver marks on a major Roman
expedition, during which he extracted the short-lived
treaty of Ponte Mammolo from Pope Paschal II in hopes
of decisively ending the Investiture Confl ict.
Matilda soon played the crucial roles of patron and
intercessor at court; she appeared on charters in subse-
quent years as the sponsor of many royal grants, and
acted as petitioner several times on behalf of nobles or
prelates who sought reconciliation with the emperor. Her
imperial role expanded when she joined her husband
on a military campaign in Rome in 1117. The imperial
army occupied the city, and Matilda was crowned with
her husband on Pentecost in St. Peter’s Basilica by the
archbishop of Braga. Matilda would choose to retain
the imperial dignity even after leaving Germany, at least
as a courtesy title. When her husband’s presence was
required north of the Alps after the coronation, Matilda
remained in Italy as imperial regent. She assisted in
the administration of imperial territories and presided
over courts such as the session at Rocca Capineta near
Reggio. She appears to have continued in this capacity
during the year 1118, and then rejoined the emperor
in Lotharingia in 1119. This royal apprenticeship at
such a tender age prepared her well for the tumultu-
ous years ahead. She was with Henry V in Utrecht at
his untimely death in 1125, which left her a childless
widow in possession of the imperial insignia at the age
of twenty-three.
Her husband’s hopes that she would produce an heir
for the Salian line were quickly replaced by her father’s
need for an heir to the Norman dynasty, since Henry
I’s only son died in 1120. He therefore recalled her to
England, and Matilda handed over the imperial insignia
to Archbishop Adalbert of Mainz before returning to her
Anglo-Norman homeland in 1125. After a sixteen–year
absence she began yet another new life, with the only
tokens of her imperial childhood in Germany being a
treasure of jewels and personal regalia (most of which
she would give to religious houses) and the precious relic
of the hand of St. James (which she gave to the family
abbey at Reading). She was recognized as the legitimate
heir of Henry I in England and Normandy, and in 1128
Henry I married her to the unpopular Angevin suitor,
Geoffrey Plantagenet. Matilda was the child in her fi rst
marriage, but in this second union Geoffrey was the
child, being ten years her junior and only fi fteen yearsMASLAMA DE MADRID