Ptolemy III Euergetes I, (Ptolemaeus III) (Evergetes, Euergetes) (246 BC-222 BC). The third ruler of the Ptolemaic dynasty of Egypt, he was the eldest son of Ptolemy II of Egypt Philadelphus and Arsinoe II of Egypt. He came to power in 246 BC upon the death of his father. He is most noted for his invasions of the northern kingdom of Syria which he commenced upon the murder of his eldest sister Berenice Phernophorus.

He married Berenice of Cyrene between 244/243 and they were parents of Arsinoe III of Egypt and Ptolemy IV of Egypt.

Ptolemy III Euergetes had put up the first of the Rosetta Stone series, the bilingual inscriptions on massive stone blocks in three writing systems. Ptolemy III's stone stela is the Canopus Stone of 238 BC. His son, Ptolemy IV, is responsible for the Memphis Stele, or Memphis Stone, the second in the series, bearing the Decree of Memphis, about 218 BC. The famous Rosetta Stone is the third, erected by Ptolemy V his grandson, in 196 BC.

Ptolemy III's stone contains decrees about priestly orders, and is a memorial for his daughter Berenice. But two of its 26 lines of hieroglyphs decree the use of a leap day added to the Egyptian calendar of 365 days, and the associated changes in festivals.

He is also credited with the foundation of the Serapeum in Alexandria.

Canopus decree of Ptolemy III : proposal to add one day every four years to keep the festivals at the right time of the year (an advice probably from Eratosthenes)

Ptolemy III

Statue of Ptolemy III in the guise of Hermes wearing the chlamys cloak. Ptolemaic Egypt.

Gold oktadrachm of Ptolemy III Euergetes

Bronze coin issued by Ptolemy III depicting (obverse) Zeus-Amun and (reverse) the traditional Ptolemaic eagle. Ptolemy III did not issue coins with his own image, c. 225 BC

Ptolemaic Egypt

Links

• Ptolemy III COINS
• Ptolemy Euergetes I at LacusCurtius (http://penelope.uchicago.edu/Thayer/E/Gazetteer/Places/Africa/Egypt/_Texts/BEVHOP/6*.html) — (Chapter VI of E. R Bevan's House of Ptolemy, 1923)
  
• Ptolemy III (http://www.tyndale.cam.ac.uk/Egypt/ptolemies/ptolemy_iii.htm) — (Royal Egyptian Genealogy)
  
• History of Greek and Roman Egypt