| From: Thomas Hockey et al. (eds.). The Biographical Encyclopedia of Astronomers, Springer Reference. New York: Springer, 2007, p. 733 |
|
Courtesy of 
|
Maʾmūn: Abū
al‐ʿAbbās ʿAbdallāh ibn Hārūn al‐Rashīd
Len Berggren
Born Baghdad, (Iraq),
14 September 786
Died near Tarsus,
(Turkey), August 833
Maʾmūn
was the son of Caliph Hārūn
al‐Rashīd, a patron of the arts whose fame has come down
to us in the tales of the Thousand and One Nights. Hārūn
also supported a fine library in Baghdad, called “The Treasure House of Wisdom,”
as well as the translation of foreign works in various fields. So Maʾmūn,
brought up in an educated environment, was not only learned in the traditional
Muslim studies but also was aware of a wider world of foreign learning. When
he came to the throne as the seventh caliph of the ʿAbbāsid
Empire in 813, he was among the well‐educated men of his time.
Maʾmūn
spent his early years as caliph consolidating his reign and building internal
unity in a diverse empire. It has been argued that part of that endeavor involved
commissioning Arabic translations of important Persian documents, as part
of a project of Arabicizing Persian learning. Since, in addition, many Persian
intellectuals believed that Greek learning was in fact based upon older Persian
learning, Maʾmūn commissioned translations of Greek material as
well. Apart from these political considerations, however, there was undoubtedly
a genuine interest on Maʾmūn's part in the learning of the Greeks.
There is also a story of a dream in which Maʾmūn saw the Greek sage,
Aristotle,
reassuring him that religion and learning were not enemies and that Maʾmūn's
support of foreign learning was not a threat to Islam.
Maʾmūn
was zealous in his search for new material and sent the scholar Salm to Byzantine
lands to buy manuscripts. (Salm also helped to improve an Arabic translation
of Ptolemy's
astronomical classic, The Almagest.) According to some reports Maʾmūn
founded, in the early 830s before his death, the Bayt al‐Ḥikma, the House of Wisdom. However, some
historians have argued that this was less a new foundation than an extension
of the Treasury of Wisdom that was already in existence at the time of Hārūn.
In any case we do know that Māʾmūn supported scholars of many
nations and professing many faiths, who studied, translated, and disseminated
wisdom and learning, particularly that of the Greeks.
In
addition to his general interest in the learning of the ancients, part of
Maʾmūn's support for astronomy was based on its utility for astrology,
a subject with which it was to be closely associated for many centuries. Whatever
the motives for his support, the result of these translation efforts was the
translation into Arabic of a number of Greek astronomical works. These included
the introductory treatises of Theodosius,
Euclid, Menelaus,
and Aristarchus,
as well as all of Ptolemy's works.
In addition to supporting the intellectual climate in which this work
could be done, Maʾmūn also sponsored two sets of observations. The
first was done in Baghdad, in 828, in the Shammāsiyya area, by astronomers
including Yaḥya ibn Abī Manṣūr and the noted
mathematician Khwārizmī.
(Two others were Sanad ibn ʿAli and ʿAbbās al‐Jawharī.) The Shammāsiyya observations were conducted
around the times of the solstices and equinoxes, and it appears that Maʾmūn
took an active interest in them. Bīrūnī
informs us in his Taḥdīd that Maʾmūn rejected the first set
of observations of 828 because of the big difference between the values for
the maximum and minimum altitudes of the Sun (at the summer and winter solstices,
respectively) at those observations and at the latter ones.
Yaḥya
died before Maʾmūn left on one of his campaigns against the Byzantines
in the early 830s. After his death, Māʾmūn decided to do new
observations at Dayr Murrān on a hill near Damascus. Accordingly, he
charged Khālid ibn ʿAbd
al‐Malik al‐Marwarrūdhī with the task of doing
observations over the period of a year with a new set of instruments. The
observations, done in two periods between 831 and 833, lasted more than a
year. They pleased Maʾmūn sufficiently for him to order that astronomical
tables be prepared on the basis of their results. Since the observations both
in Damascus and Baghdad seem to focus entirely on the Sun and Moon, these
tables must have reflected earlier material for planetary motions.
Quite apart
from these undoubted contributions to astronomy, Maʾmūn furnished
an example of the type of a ruler that found many echoes in medieval Islam.
The result was the development of the observatory as a new scientific institution,
a development directly inspired by Maʾmūn, and, more generally,
a tradition of royal patronage of astronomy.
Selected References
Ali, Jamil (trans.) (1967). The Determination of the Coordinates
of Cities: Al‐Bīrūnī's Taḥdīd al‐Amākin.
Beirut: American University of Beirut.
Gutas,
Dimitri (1998). Greek Thought, Arabic Culture: The Graeco‐Arabic
Translation Movement in Baghdad and Early ʿAbbāsid
Society (2nd–4th/8th–10th centuries). London: Routledge.
Rekaya,
M. (1991). “al‐Maʾmūn, Abu ʾl‐ʿAbbās.”
In Encyclopaedia of Islam. 2nd edn. Vol. 6, pp. 331–339. Leiden: E.
J. Brill.
Sayılı,
Aydın (1960). The Observatory in Islam. Ankara: Turkish Historical
Society.