Claudius Ptolemaeus

Almost nothing about Ptolemy's personal life is documented. He is generally dated to circa 100 to circa 170 CE and is placed in Alexandria, Roman Egypt, but no source consulted gives an exact birth or death date, only proposed ranges that place his death anywhere from about 165 to about 178 CE. No school, degree, or course of study is recorded for him. Historians have proposed, based on dedications in his own texts, that Theon and possibly a figure named Syrus may have been his teachers in Alexandria, but this is inference rather than a documented record.

His three major surviving works are the Almagest, a comprehensive astronomical treatise that set out a geocentric model of the cosmos; the Geography, which introduced a coordinate grid of latitude and longitude for mapping the known world; and the Tetrabiblos, a foundational astrological text. These works were transmitted through manuscript copies for centuries before entering print in the Renaissance. Later printed editions, including a Bologna edition and a Ulm edition referenced in library and auction records, carried his geographic and astronomical models into the age of print and eventually into the modern antiquarian trade.

Scholarly consensus credits the Almagest's geocentric model with dominating Western and Islamic astronomy until Copernicus, and the Geography's coordinate grid method with founding later cartographic practice. Historians of science consistently treat him as one of the most influential technical authors of antiquity, even though almost nothing is known about him personally. No exact, attributable verbatim quotes from named critics in major outlets were located in the sources reviewed, so none are reproduced here.

There is no primary-market gallery or estate for Claudius Ptolemaeus. What trades under his name are manuscripts, early printed editions of his texts, and maps derived from his Geography, sold through rare book, map, and antiquities specialists rather than contemporary art dealers. The highest price located in research is USD 329,400, reported for a 1513 edition of the Geographia in a prices-realized list dated April 18, 2015; the auction house itself is not identified in that source, so the result should be treated as the best documented figure available rather than a fully corroborated record. For context, a 1486 Ulm edition world map attributed to Ptolemy sold for USD 200,000 at Brunk Auctions, and a 2013 Sotheby's lot carried an estimate of GBP 600,000 to 800,000 but closed without a confirmed price realized. Trading in these objects is thin and irregular, with no continuous price series and no computed market metrics available for this figure in the sources reviewed.

A collector encountering "Claudius Ptolemaeus" in the market is almost always looking at an antiquarian printed edition or a map derived from his Geography, not a unique artwork by his hand. There is no catalogue raisonne, no gallery or estate representation, and no comprehensive public census of institutional holdings beyond the specific library record documented here. Edition, printer, plate condition, and provenance matter more than attribution in the conventional sense, and the auction history is thin enough, resting on a small number of documented sales, that any single price point should be read with caution rather than treated as a stable benchmark.