Ptolemy Keraunos
His mother only held control of the Aegean part of his father's kingdom. After the death of his father, Arsinoe II and her sons fled to Cassandreia. In order to protect, secure Arsinoe II and her son's sovereignty and his father's kingdom, Ptolemy's mother married his maternal uncle Ptolemy Keraunos, who was his mother's older paternal half-brother. Ptolemy Keraunos lived in his father's kingdom as a political exile and prior to marrying his mother had murder Seleucus I in order to gain the power of his former protector and then rushed to Lysimachia where he had himself acclaimed king by the Macedonian army.