Ptolemy

2nd-century Roman mathematician, astronomer, geographer
Person human Q34943
Ptolemy
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Summary

Ptolemy was born on 100[1] in Ptolemais Hermiou[2]. He died on 170[3] in Alexandria[4]. He worked as a mathematician[5], geographer[6], astronomer[7], astrologer[8], and music theorist[9]. He ranks in the top 0.56% of human entities by monthly Wikipedia readership (23,417 views/month, #5,598 of 1,000,298).[10]

Key Facts

  • Place of death: Canopus[11]
  • Date of birth: January 1, 87[12], 85[13]
  • Date of death: 165[14]
  • Country of citizenship: Ancient Rome[15]
  • Occupation: philosopher[16], musicologist[17], epigrammatist[18], writer[19], naturalist[20]
  • Field of work: astronomy[21], astrology[22], mathematics[23], mechanics[24], optics[25], geography[26], music theorist[27], music theory[28]
  • Employer: Library of Alexandria[29]
  • Notable work: Almagest[30], Geography[31], List of Roman emperors[32], Ptolemaic map[33], Ptolemy's intense diatonic scale[34], Ptolemy's table of chords[35], Ptolemy's inequality[36], Ptolemy's theorem[37], equant[38], quadrant[39], Tetrabiblos[40], Handy Tables[41]
  • Influenced by: Aristotle[42]
  • Sex or gender: male[43]
  • Commons category: Ptolemy[44]
  • Residence: Alexandria[45]
  • Given name: Ptolemaios[46]
  • Topic's main category: Category:Ptolemy[47]
  • Commons gallery: Κλαύδιος Πτολεμαῖος[48]

Body

Works and Contributions

Things named for Ptolemy include his world map[49], his theorem[50], Lake Ptolemy[51], his inequality[52], Ptolemaeus[53], 4001 Ptolemaeus[54], Mount Ptolemy[55], and Ptolémée Prize[56].

Why It Matters

Ptolemy has Wikipedia articles in 30 language editions, a strong signal of global cultural recognition.[57] He is known by 134 alternative names across languages and contexts.[58]

He has been cited as an influence by Christopher Columbus[59], an explorer[60], 1450–1506[61], of Republic of Genoa[62], specialised in sea shipping[63]; Nicolaus Copernicus[64], an astronomer[65], 1473–1543[66], of Kingdom of Poland[67], awarded the International Space Hall of Fame[68], specialised in astronomy[69]; Hypatia[70], a mathematician[71], 0360–0415[72], of Byzantine Empire[73], specialised in astronomy[74]; and Al-Battani[75], a mathematician[76], 0858–0930[77], specialised in astronomy[78].

He is credited with the discovery of Argo Navis[79], a former constellation[80]; equant[81], a mathematical concept[82]; and Messier 7[83], an open cluster[84]. Works attributed to him include Almagest[85], a literary work[86], founded in 0148[87]; Geography[88]; and Tetrabiblos[89]. Entities named for him include his world map[49], his theorem[50], Lake Ptolemy[51], his inequality[52], Ptolemaeus[53], and 4001 Ptolemaeus[54].

FAQs

Where was Ptolemy born?

Ptolemy was born in Ptolemais Hermiou[2].

Where did Ptolemy die?

Ptolemy passed away in Alexandria[4].

What did Ptolemy do for work?

Ptolemy worked as a mathematician[5], geographer[6], astronomer[7], astrologer[8], and music theorist[9].

Who did Ptolemy influence?

Ptolemy has been cited as an influence by Christopher Columbus[59], Nicolaus Copernicus[64], Hypatia[70], and Al-Battani[75].

What did Ptolemy discover?

Ptolemy is credited as discoverer of Argo Navis[79], equant[81], and Messier 7[83].

References

Programmatic citations — every numbered marker resolves to a verifiable graph row below.

Direct Wikidata claims

  1. [2] ↑ . Encyclopedia.com. Retrieved . wikidata.org.
  2. [4] ↑ . MacTutor History of Mathematics archive. Retrieved . www-history.mcs.st-andrews.ac.uk. Provenance: wikidata.org.
  3. [11] ↑ . Encyclopédie Larousse. Retrieved . wikidata.org.
  4. [43] ↑ . BnF authorities. Retrieved . wikidata.org.
  5. [15] ↑ . wikidata.org.
  6. [21] ↑ . wikidata.org.
  7. [22] ↑ . wikidata.org.
  8. [23] ↑ . wikidata.org.
  9. [24] ↑ . wikidata.org.
  10. [25] ↑ . wikidata.org.
  11. [26] ↑ . wikidata.org.
  12. [27] ↑ . wikidata.org.
  13. [28] ↑ . wikidata.org.
  14. [5] ↑ . The Fine Art Archive. Retrieved . wikidata.org.
  15. [6] ↑ . The Fine Art Archive. Retrieved . wikidata.org.
  16. [7] ↑ . The Fine Art Archive. Retrieved . wikidata.org.
  17. [8] ↑ . Integrated Authority File. Retrieved . wikidata.org.
  18. [9] ↑ . wikidata.org.
  19. [16] ↑ . Integrated Authority File. Retrieved . wikidata.org.
  20. [17] ↑ . wikidata.org.
  21. [18] ↑ . wikidata.org.
  22. [19] ↑ . Library of the World's Best Literature. wikidata.org.
  23. [20] ↑ . Integrated Authority File. Retrieved . wikidata.org.
  24. [29] ↑ . wikidata.org.
  25. [44] ↑ . wikidata.org.
  26. [45] ↑ . wikidata.org.
  27. [1] ↑ . BnF authorities. Retrieved . wikidata.org.
  28. [12] ↑ . wikidata.org.
  29. [13] ↑ . MacTutor History of Mathematics archive. wikidata.org.
  30. [3] ↑ . BnF authorities. Retrieved . data.bnf.fr. Provenance: wikidata.org.
  31. [14] ↑ . MacTutor History of Mathematics archive. wikidata.org.
  32. [46] ↑ . wikidata.org.
  33. [42] ↑ . wikidata.org.
  34. [30] ↑ . wikidata.org.
  35. [31] ↑ . wikidata.org.
  36. [32] ↑ . wikidata.org.
  37. [33] ↑ . wikidata.org.
  38. [34] ↑ . wikidata.org.
  39. [35] ↑ . wikidata.org.
  40. [36] ↑ . wikidata.org.
  41. [37] ↑ . wikidata.org.
  42. [38] ↑ . wikidata.org.
  43. [39] ↑ . wikidata.org.
  44. [40] ↑ . wikidata.org.
  45. [41] ↑ . wikidata.org.
  46. [47] ↑ . wikidata.org.
  47. [48] ↑ . wikidata.org.

Inverse relationships (entities pointing at this one)

  1. [59] ↑ . wikidata.org. → on this site
  2. [64] ↑ . wikidata.org. → on this site
  3. [70] ↑ . wikidata.org. → on this site
  4. [75] ↑ . wikidata.org. → on this site
  5. [79] ↑ . wikidata.org. → on this site
  6. [81] ↑ . wikidata.org. → on this site
  7. [83] ↑ . wikidata.org. → on this site
  8. [85] ↑ . wikidata.org. → on this site
  9. [88] ↑ . wikidata.org. → on this site
  10. [89] ↑ . wikidata.org. → on this site
  11. [49] ↑ . wikidata.org. → on this site
  12. [50] ↑ . wikidata.org. → on this site
  13. [51] ↑ . wikidata.org. → on this site
  14. [52] ↑ . wikidata.org. → on this site
  15. [53] ↑ . wikidata.org. → on this site
  16. [54] ↑ . wikidata.org. → on this site
  17. [55] ↑ . wikidata.org. → on this site
  18. [56] ↑ . wikidata.org. → on this site

Inline context (facts about related entities)

  1. [60] ↑ . Wikidata. wikidata.org. → on this site
  2. [61] ↑ . Wikidata. wikidata.org. → on this site
  3. [62] ↑ . Wikidata. wikidata.org. → on this site
  4. [63] ↑ . Wikidata. wikidata.org. → on this site
  5. [65] ↑ . Wikidata. wikidata.org. → on this site
  6. [66] ↑ . Wikidata. wikidata.org. → on this site
  7. [67] ↑ . Wikidata. wikidata.org. → on this site
  8. [68] ↑ . Wikidata. wikidata.org. → on this site
  9. [69] ↑ . Wikidata. wikidata.org. → on this site
  10. [71] ↑ . Wikidata. wikidata.org. → on this site
  11. [72] ↑ . Wikidata. wikidata.org. → on this site
  12. [73] ↑ . Wikidata. wikidata.org. → on this site
  13. [74] ↑ . Wikidata. wikidata.org. → on this site
  14. [76] ↑ . Wikidata. wikidata.org. → on this site
  15. [77] ↑ . Wikidata. wikidata.org. → on this site
  16. [78] ↑ . Wikidata. wikidata.org. → on this site
  17. [80] ↑ . Wikidata. wikidata.org. → on this site
  18. [82] ↑ . Wikidata. wikidata.org. → on this site
  19. [84] ↑ . Wikidata. wikidata.org. → on this site
  20. [86] ↑ . Wikidata. wikidata.org. → on this site
  21. [87] ↑ . Wikidata. wikidata.org. → on this site

Aggregate / graph-position facts

  1. [10] ↑ . Wikimedia Foundation. dumps.wikimedia.org.
  2. [57] ↑ . Wikidata sitelinks. wikidata.org.
  3. [58] ↑ . Wikidata aliases. wikidata.org.

📑 Cite this page

Use these citations when quoting this entity in research, articles, AI prompts, or wherever provenance matters. We aggregate Wikidata + Wikipedia + authoritative open-data sources; the stitched, scored, cross-referenced view is what 4ort.xyz contributes.

APA 4ort.xyz Knowledge Graph. (2026). Ptolemy. Retrieved October 14, 2026, from https://4ort.xyz/entity/ptolemy
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BibTeX @misc{4ortxyz_ptolemy_2026, author = {{4ort.xyz Knowledge Graph}}, title = {{Ptolemy}}, year = {2026}, url = {https://4ort.xyz/entity/ptolemy}, note = {Accessed: 2026-10-14}}
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Edit History

Rolling log of changes to this entity's Wikidata record. Values shown reflect the current state of each edited property — follow the history link to see the precise diff for any edit.

  1. 2d ago · Dodro · 2026-10-14 view diff on Wikidata ↗
    Galiciana authority id → 15407
    Claims rich → —
    "/* wbsetclaim-update:2||1 */ Galiciana authority id: 15407"
  2. 9d ago · Printstream · 2026-10-06 view diff on Wikidata ↗
    Wikipedia languages → ['af', 'als', 'am', 'an', 'ar', 'ary', 'arz', 'ast', 'az', 'ba', 'bcl', 'be', 'b
    Claims rich → —
    "/* wbeditentity-update-languages-short:0||de */ QuickStatements 3.0 [[:toollabs:qs-dev/batch/57891|batch #57891]]: Import missing aliases from dewiki 1/5"
  3. 29d ago · Ontogon · 2026-09-16 view diff on Wikidata ↗
    Iași central university library id → 002327241
    "/* wbsetclaim-create:2||1 */ Iași central university library id: 002327241"
  4. 8w ago · Mahirtwofivesix · 2026-08-19 view diff on Wikidata ↗
    Babelnet id → 00019602n
    Arabic ontology lexical concept id → 151061151
    "/* wbeditentity-statements-multiple-properties-update:0||4 */ added/modified IDs mapped to WordNet 3.1"
  5. 8w ago · Charp238 · 2026-08-18 view diff on Wikidata ↗
    Jewish virtual library id → ptolemy-the-geographer-x00b0
    "/* wbsetclaim-update:2||1|1 */ Name in native language: Κλαύδιος Πτολεμαῖος"
  6. 11w ago · Pierrotrgr · 2026-07-24 view diff on Wikidata ↗
    Biblissima authority id → Freguesia de Cepos
    "/* wbsetclaim-create:2||1 */ Biblissima authority id: Q3210, Import ID Biblissima V3 ([[:toollabs:editgroups/b/OR/a6710164cdc|details]])"
  7. 12w ago · Putnik · 2026-07-20 view diff on Wikidata ↗
    Visuotinė lietuvių enciklopedija id → klaudijas-ptolemajas
    "/* wbsetclaim-create:2||1 */ Visuotinė lietuvių enciklopedija id: klaudijas-ptolemajas"
  8. 13w ago · Nyuhn · 2026-07-10 view diff on Wikidata ↗
    P14541 → 1UsV38
    "/* wbeditentity-update:0| */ QuickStatements 3.0 [[:toollabs:qs-dev/batch/40849|batch #40849]]: ZGBK ID"
  9. 14w ago · Printstream · 2026-07-04 view diff on Wikidata ↗
    P14608 → 118641786
    "/* wbcreateclaim-create:1| */ P14608: 118641786, #quickstatements; #temporary_batch_1783130387391"
  10. 15w ago · Printstream · 2026-07-01 view diff on Wikidata ↗
    P14585 → 65136
    "/* wbcreateclaim-create:1| */ P14585: 65136, #quickstatements; #temporary_batch_1782930557898"
  11. 15w ago · Bargioni · 2026-07-01 view diff on Wikidata ↗
    Parsifal cluster id → 288841, 545635
    "/* wbeditentity-update:0| */ QuickStatements 3.0 [[:toollabs:qs-dev/batch/39443|batch #39443]]: sync P12458"
  12. 15w ago · Bargioni · 2026-06-28 view diff on Wikidata ↗
    Parsifal cluster id → 288841, 545635
    "/* wbeditentity-update:0| */ QuickStatements 3.0 [[:toollabs:qs-dev/batch/38956|batch #38956]]: add P1810 to P12458"
  13. 15w ago · Epìdosis · 2026-06-27 view diff on Wikidata ↗
    Parsifal cluster id → 288841, 545635
    "/* wbcreateclaim-create:1| */ Parsifal cluster id: 545635, [[:toollabs:quickstatements/#/batch/259855|batch #259855]]"
  14. 15w ago · Printstream · 2026-06-26 view diff on Wikidata ↗
    P14536 → 380295
    "/* wbcreateclaim-create:1| */ P14536: 380295, #quickstatements; #temporary_batch_1782462304762"
  15. 17w ago · Gerwoman · 2026-06-13 view diff on Wikidata ↗
    National library of spain spmabn id (bne v1.0) → XX1136821, XX4879993
    "/* wbcreateclaim-create:1| */ National library of spain spmabn id (bne v1.0): XX4879993, [[:toollabs:quickstatements/#/batch/259615|batch #259615]]"
  16. 18w ago · Jindřich Rubeš · 2026-06-11 view diff on Wikidata ↗
    Svkkl authority id → 0233845-Ptolemaios-Klaudios-asi-100178
    "/* wbcreateclaim-create:1| */ Svkkl authority id: 0233845-Ptolemaios-Klaudios-asi-100178, [[:toollabs:quickstatements/#/batch/259495|batch #259495]]"
  17. 21w ago · Epìdosis · 2026-05-20 view diff on Wikidata ↗
    Local thumb → —
    Occupation → mathematician, geographer, astronomer +7
    "/* wbeditentity-update:0| */ QuickStatements 3.0 [[:toollabs:qs-dev/batch/32084|batch #32084]]: import P21 and P106 from GND (26)"
  18. 23w ago · HannoWij · 2026-05-06 view diff on Wikidata ↗
    Bibale id → 55947
    Local thumb → —
    "/* wbsetclaim-create:2||1 */ Bibale id: 55947"
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