Ptolemy III Euergetes | Macedonian King of Egypt
He was the eldest son of Ptolemy II and Queen Arsinoe I. Arsinoe II adopted him after she succeeded in making Ptolemy abandon his mother and exile her to Asia Minor, and Ptolemy III was officially considered the son of Arsinoe II. His son succeeded him on the throne in 246 B.C.
He seems to have had good qualities and perhaps the reason behind the nickname “Euergetes” is because he ordered the dropping of taxes imposed on the people in recognition of the famine conditions that the country went through, and he was, like his father, a lover of science and culture.
However, he was distinguished from his father in that he was of high moral character and had no concubines, and he had one wife, “Brinke,” and the result of this marriage was the annexation of Qarniqa to the Egyptian state. He was nominally involved with his father in governing the country for a period of time (he was just a spectator), so he reached adulthood without learning the art of governing and the politics of the king.
In fact, Ptolemy III's activity was most notable in other fields, notably his promotion of science, literature, agriculture, and religion in particular. Ptolemy III is indisputably no less than his father in promoting science and literature; he added so much to the Library of Alexandria that he was sometimes mistakenly credited as its founder because of the number of books he collected and added to it.