Ptolemaios

Ptolemaios is the Greek form of the personal name Ptolemy, used in the Hellenistic world and in later Greek sources. It is associated with a number of notable figures, most prominently in the royal line of the Ptolemaic Kingdom in Egypt and with the Alexandrian astronomer Claudius Ptolemaeus.

In Egypt, the name Ptolemaios was borne by members of the Ptolemaic dynasty, the Greek Macedonian royal house that ruled Egypt after the death of Alexander the Great. The dynasty was founded by Ptolemy I Soter (Ptólemaios Sótēr), a general of Alexander, who reigned from the early 3rd century BCE and established Greek rule in Egypt. His successors, including Ptolemy II Philadelphus and Ptolemy III Euergetes, extended the dynasty’s territorial reach and oversaw significant cultural activity in Alexandria, home to the Library and the Museum. The name continued to be used by later Ptolemaic rulers such as Ptolemy IV Philopator and Ptolemy V Epiphanes, among others, as part of an established royal titulary.

In science, Claudius Ptolemaeus (Ptólemaios) was a Greco-Egyptian astronomer and geographer of the 2nd century CE. His works, the Almagest and the Geography, presented a comprehensive geocentric model of the cosmos and a detailed system of mathematical astronomy and cartography that influenced medieval and Renaissance science.

The given name Ptolemaios thus spans both royal and scholarly traditions in the ancient world, with alternative transliterations including Ptolemy (English) and Ptolemaeus (Latin).