Ptolemy II
Ptolemy II was the eldest son of Ptolemy I by his third wife, Bernice. He was born in the island of Kous in the Mediterranean Sea during one of his father's campaigns there. He was spoiled with a mild nature and character. He had a tendency to obesity and obesity was a distinctive feature of the Ptolemaic Kings. After the death of his father, he left to Egypt taking with him his brother, wife and children. He was in his twenties when he ascended the throne. He made a great celebration for his coronation, a celebration that cost the country a large sum of money. Ptolemy II was very interested in learning and provided himself with the best scholars. He developed an interest in zoology, history and philosophy more than his interest in ruling the country. Ptolemy II married two women, both of them were called Arisnoe. Arisnoe I was the daughter of Lysimachus (who was one of the bodyguards of Alexander the Great, the ruler of Thrace and a friend of Ptolemy I. Ptolemy I arranged for a marriage between his son Ptolemy II and Arisnoe I. At the same time, Arisnoe (later Arisnoe II) was the sister of Ptolemy II. So, Ptolemy II married to Arisnoe I (the daughter of Lysimachus) and Lysimachus married to Arisnoe II (the daughter of Ptolemy I and sister of Ptolemy II). Arisnoe, wife of Lysimachus, was about 17 years old while he was aging about 60. This difference in age resulted in Arisnoe taking the full control and authority on Lysimachus as she was an ambitious woman. Lysimachus had a son called Agathacoles by a previous wife.
 Agathacoles was Lysimachus' eldest son and was liked by the people and the army of Thrace. And, Agathacoles was supposed to be the heir of the throne after his father. When Lysimachus married Arisnoe II, she gave birth to three sons and once they started to grow up, she decided that one of them should succeed Lysimachus to the throne of Thrace. She decided to get rid of Agathacoles who was the legal heir to the throne. To reach her goal, she plotted against him accusing him of trying to kill his father. As a result, Agathacoles was put on a trial, found guilty and then executed. His widow, mother and children left Thrace and went to Macedonia. This act upset the Hellenistic World, driving the Macedonian king to declare war against Lysimachus. At that time, there was a man with the name Karnos was dwelling Macedonia. Karnos was the eldest son of Ptolemy I from his second wife Euridike. 
 Karnos left Egypt with his family after the ascension of his half-brother Ptolemy II to the throne and went to Macedonia supporting the Macedonian King in his decision to declare war against Lysimachus. The war began between Lysimachus and Macedonian King. In one of the battles, Lysimachus was killed and his wife Arisnoe escaped from the royal palace with her children to the borders of Thrace. Then Karnos killed the Macedonian King and became the King of Macedonia. Karnos offered himself to marry Arisnoe. Accepting his offer, she married him and they began to rule together. After a short period of time, he found out that with her bad character, she is difficult to be controlled. This acknowledgment made him decide to kill her and her children as well. But she succeeded in escaping with her eldest son after Karnos killed her other two sons. However, before she left Thrace, Karnos' attempt this time was successful and he killed her eldest son, yet, she managed to flee to Egypt and to stay at Alexandria. She went to her brother Ptolemy II. She plotted against the wife of her brother, Arisnoe I, and as a result Arisnoe I wife of Ptolemy II was put on a trial and she was found guilty so she was exiled to Coptos which was the fifth Nome of Upper Egypt. Ptolemy II married his sister, Arisnoe, and took the title of Philadelophos and she became Arisnoe II. 
 When Ptolemy II married Arisnoe II she was about 40 years old. The Egyptians accepted this marriage or the marriage of siblings and they considered it as a return to the old traditions. However, the Greeks considered the marriage of siblings as a vile action because this type of marriage was unknown to and strange within the Hellenistic World. However, some of the Greeks justified it as Arisnoe II became old in age. Due to her age, Arisnoe II couldn’t give Ptolemy II any children and as a result, she took the children of Arisnoe I and brought them up as her own children. Ptolemy II left Arisnoe II to rule the country and run its affairs. He paid his great attention to learning zoology, history and philosophy. But, unfortunately Arisnoe II died 7 years after her return to Egypt. After her death, Ptolemy II never married and he started to run the affairs Egypt again. 
 Ptolemy II deified both his mother and his father. During his reign, Egypt continued to be prosperous and flourished due to his encouragement to the scientists and bankers to come to Egypt. He was very interested in the library of Alexandria which was started by his father Ptolemy I and completed by Ptolemy II. He provided the library with a great deal of books and he borrowed and bought a large amount of books from Athens to copy them. These actions made him lose a large sum of money to borrow these books. He ordered Manetho to write the history of Egypt. Moreover, whenever any one was to visit Egypt Ptolemy II gave him a book as a present. He followed the same policy of his father as he followed the monopoly system, barter system, irrigation system, importing some exotic animals, birds and plant and he didn’t allow Egyptians to be recruited in the Ptolemaic army.
At the end of his reign, Magas (who was the ruler of Libya) planned to attack Egypt. However, Ptolemy II wanted to avoid war so Ptolemy II suggested that his son Ptolemy III marry the daughter of Magas and she was called Bernice II and Magas accepted this offer and Ptolemy II managed to avoid the war. Ptolemy II took his son Ptolemy III as a co-regent for two years and then he died when he was 60 years old after ruling the country for 38 years. Unfortunately, we don’t know the details of his reign,