# Astrolabe of 'Umar ibn Yusuf ibn 'Umar ibn 'Ali ibn Rasul al-Muzaffari > 'Umar ibn Yusuf ibn 'Umar ibn 'Ali ibn Rasul al-Muzaffari, later Sultan al-Malik al-Ashraf 'Umar II - 690 AH / 1291 CE > Canonical HTML: https://iconotheca.com/artworks/umar-ibn-yusuf-al-muzaffari/astrolabe-al-muzaffari-met/ > Published by Servola Systems GmbH. Last verified: 2026-08-27 ## Tombstone - **Artist:** 'Umar ibn Yusuf ibn 'Umar ibn 'Ali ibn Rasul al-Muzaffari, later Sultan al-Malik al-Ashraf 'Umar II - **Date:** 690 AH / 1291 CE - **Medium:** Brass, cast and hammered, pierced, chased, and inlaid with silver - **Dimensions:** Case: diameter 15.6 cm, width 19.4 cm, depth 0.6 cm. Net (rete): diameter 12.7 cm. Four plates: diameter 12.7 cm each. Bar with attached nail: length 12.7 cm. Pin: length 4.4 cm, width 1.3 cm. - **Object type:** Clocks and instruments - **Period:** Rasulid Yemen, late 13th century - **Current location:** Metropolitan Museum of Art, New York, Department of Islamic Art - **Attribution:** accepted ## Summary A brass astrolabe signed and dated 690 AH / 1291 CE by its maker, a Rasulid prince of Yemen who three or four years later briefly ruled the kingdom as Sultan al-Ashraf 'Umar II. It is one of the small number of medieval Islamic scientific instruments whose maker also left behind his own written manual on how to build it, complete with notes from two teachers certifying his skill. The astrolabe's rete carries an unusual scale for the lunar mansions, and its plates are engraved for the latitudes of Yemen and the Hejaz using the tables set out in that same manual rather than by direct geometrical construction.Nothing is recorded of the object between its making in 1291 and its appearance, roughly six centuries later, in the New York collection of the Tiffany silversmith and pioneer collector of Islamic art Edward C. Moore, who bequeathed it to the Metropolitan Museum in 1891. It has been in the Museum's Department of Islamic Art ever since. ## Provenance Every link carries a grade. `documented` means a cited source supports it, `disputed` means the identification is argued but not established, `unknown` means we have no owner for that span and have not bridged it. - **690 AH / 1291 CE** 'Umar ibn Yusuf ibn 'Umar ibn 'Ali ibn Rasul al-Muzaffari `[documented]` (manufacture) Signed and dated by the maker in the instrument's own inscription. Made several years before he became sultan. - **1291-before 1891** Unknown `[unknown]` (gap) No owner, transaction, gift or seizure is named in any source consulted for this record across a span of roughly six centuries. This is recorded as a gap, not bridged by inference. - **before 1891-1891** Edward C. Moore, New York `[documented]` (private collection) Moore, a Tiffany and Co. silversmith and one of the earliest serious American collectors of Islamic art, owned the astrolabe by the time of his death in 1891; how and when he acquired it is not documented in the sources consulted. - **1891-present** Metropolitan Museum of Art, New York `[documented]` (bequest) Accessioned as 91.1.535a-h under the Edward C. Moore Collection, Bequest of Edward C. Moore, 1891, part of a gift of roughly four hundred Islamic-world objects, the Museum's first major group of Islamic art. ## Open questions - Where was the astrolabe, and in whose hands, between its completion in 1291 and its documented presence in Edward C. Moore's New York collection before his death in 1891? No owner across that roughly six-century span is named in the sources consulted. - How and when did Edward C. Moore acquire the astrolabe? No dealer, sale, or intermediary owner is identified in the sources consulted. - Which specific towns' latitudes are engraved on the four surviving plates? The academic literature describes them only as covering Yemen and the Hejaz generally, without itemizing the plates by named locality. - Why do the star pointers fitted to the rete not match the star positions tabulated in the maker's own treatise, given that the instrument's back and the treatise's diagram of a back are otherwise closely matched? - Is this specific astrolabe one of the four to six instruments that the maker's two teachers examined and certified, or a work outside that certification? The certifying notes do not identify the instruments they cover by any description that can be matched to this one. - What did the Metropolitan Museum's internal appraisal of the 1891 Moore bequest, if one survives, record for this object? Not published in the sources consulted. ## Sources - [1] Metropolitan Museum of Art, Collection API, object record for ID 444408 (accession 91.1.535a-h), confirmed directly. - [2] Metropolitan Museum of Art, object page for this astrolabe. - [3] Petra G. Schmidl, 'Ashraf: al-Malik al-Ashraf (Mumahhid al-Din) 'Umar ibn Yusuf ibn 'Umar ibn 'Ali ibn Rasul,' in Thomas Hockey et al. (eds.), The Biographical Encyclopedia of Astronomers (Springer, 2007), pp. 66-67, as hosted by the Islamic Scientific Manuscripts Initiative (ISMI), Max Planck Institute for the History of Science. This entry cites and draws on David A. King, 'The Medieval Yemeni Astrolabe in the Metropolitan Museum of Art in New York City,' Zeitschrift fur die Geschichte der Arabisch-Islamischen Wissenschaften 2 (1985), pp. 99-122, which this desk has not independently examined and which is flagged for direct consultation. - [4] Wikimedia Commons, licensing metadata (LicenseShortName: CC0) for the lead image file, verified via the Commons API. - [5] Wikimedia Commons, licensing metadata (LicenseShortName: CC0) for the companion documentation photographs of the same accession, verified via the Commons API. - [6] Wikipedia, 'Al-Ashraf Umar II.' Tertiary source, used only for cross-checking reign dates and family relations already given by Schmidl; flagged for replacement with direct consultation of King (1985) and Varisco. - [7] Wikipedia, 'Al-Muzaffar Yusuf I.' Tertiary source, used only for the father's reign dates and succession; flagged for replacement. - [8] Discover Islamic Art (Museum With No Frontiers), database entry on this astrolabe. Tertiary source; its claim that the maker's treatise 'specifically describes this piece' is looser than Schmidl's more careful statement that the connection between instrument and text is definite, and this record follows Schmidl's phrasing rather than this one. Flagged for replacement. - [9] Metropolitan Museum of Art, exhibition and curatorial material on Edward C. Moore's collection of Islamic art and its 1891 bequest to the Museum. - [10] Metropolitan Museum of Art, Collection API, object record for ID 444540 (Brazier of al-Malik al-Muzaffar Shams al-Din Yusuf ibn 'Umar, accession 91.1.540), confirmed directly. - [11] Wikipedia, 'Al-Afdal al-Abbas.' Tertiary source, used only for general context on continuing Rasulid royal scholarly patronage after this maker's death; flagged for replacement. --- Images on this record are public domain or CC0 and are hosted by us. No image on this site is generated or simulated. If you quote this record, quote the provenance grades with it.