The real details of the astrolabe’s invention in ancient Greece have largely been lost. The third century BC mathematician Apollonius, of what is now Turkey, may have invented its stereographic projection of the celestial sphere. And the astronomer Hipparchus may have been familiar with that projection during the next century, or may have even invented the astrolabe then. A useful but inaccurate Islamic myth is that Ptolemy discovered the astrolabe when his celestial globe dropped under the hooves of his donkey. The astrolabe does resemble a celestial globe or armillary sphere that has been “flattened” into two dimensions. And its basic design has not changed over the millennia but only been enhanced by many different features.

c. 1600
Maker Unknown
Presented by A.E. Gunther
This astrolabe was first donated to the University in 1659 by Nicholas Greaves, the brother of John Greaves the Savilian Professor of Astronomy at Oxford. The rete is similar to that of an astrolabe signed by the well-known British instrument maker Humfrey Cole, now at the British Museum.

Astrolabe, Persian
984/5 or 1003/4 AD (Dated 374 or 394 A.H.)
Made by Ahamad and Muhammad, Sons of Ibrahim,
Isfahan, Iran
Lewis Evans Collection
This earliest-known Persian astrolabe is topped by the large triangular ornament and Kufic script characteristic of its origins. It has an astrological table on the back with planetary symbols derived from Greek antiquity.

Armillary Sphere, Ptolemaic
Made by Carlo Plato
From the Sestieri Collection, Rome
This armillary sphere shows the sun and moon revolving around a stationary earth, with the moon on a separate orbit. Individual stars are noted on the rings and pointers.


The name “astrolabe” probably comes from the Arabic version of the Greek term “star holder.” As early as the fourth century AD, Greek astronomical texts were being translated into Syriac and Arabic and filtering into the Islamic world. The astronomer Nastulus, of what is now Iraq, made the earliest surviving astrolabe circa 927/8. Islamic astrolabes are unique in the degree to which they assist the religion founded by the Prophet Muhammad in the seventh century AD. Their features include tools for judicial astrology, for determining the five or more prayer times of each day, and for finding the direction of Mecca.

Astrolabe with geared calendar
1221/2 (dated 618 A.H.)
Made by Muhammad, born Abi Bakr
Isfahan, Iran
Brass and Silver
Lewis Evans Collection
This is the oldest complete, geared machine in existence. Moving the astrolabe’s rete moves the gears on the back. This reveals the lunar phase, the lunar date, and the positions of the sun and moon through three apertures in the mater.


Astrolabe Quadrant
1682/3 (dated 1094 A.H.)
Made by Ahmad al-Ayyûbî'
Lacquered Wood
This Prophatius style astrolabe quadrant also has an horary quadrant for telling time. The two projections on its side are sights. The back features a trigonometric graph.

Made by Qa’im Muhammad
Lahore, Pakistan
Lewis Evans Collection
This astrolabe’s rete depicts 50 stars, and the mater features a gazetteer of the longitudes and latitudes of 120 locations. The back includes an astrological table of the planets, and unusual scales of the Syrian solar months and the 28 mansions of the moon.


In the eighth century AD, the Islamic world extended into Spain. It was from there that Greek and Islamic texts on the astrolabe were translated into Latin and reintroduced into Europe. Hermann “the Lame” wrote of the instrument in the 11th century, as did Chaucer at the end of the 14th century. At about the same time as Chaucer, Jean Fusoris of Paris established the fist known commercial instrument workshop in Europe. European makers rediscovered and improved older Islamic designs and added their own stylistic hallmarks. For example, the retes on Flemish astrolabes like that on this shelf by Arsenius, mimic tulips. Soon the astrolabe was being produced for all types of astronomy, navigation and surveying. But other instruments began to replace it in Europe in the 17th century, and later in some parts of the Islamic world.

Made by Qassim 'Ali Qa'inbi
Billmeir Collection. Formally in the Chadenat Collection
The basmalah - “In the name of Allah, the compassionate, the merciful” - has been incorporated into this rete’s ecliptic circle. The bird on the rete represents the “falling vulture” star, Alpha Lyræ. The mater is engraved with a gazetteer indicating the longitude, latitude, and distance from Mecca of almost 40 cities and towns.