An aristocratic Roman of consummate political skills and, for much of his career, remarkable good fortune, Caesar elevated himself from relative poverty and obscurity to a position of supreme authority over the entire Roman world. In his long-drawn rivalry with Pompey the Great he became involved in a series of long campaigns across the Empire. He gained control of Pompey's power base in Spain and them pursued him to Greece; Pompey fled to Egypt, where he was murdered in 48 BC. Caesar entered Egypt and became committed to the support of the Ptolemaic queen Cleopatra VII in her conflict with her brother, Ptolomy XIII. He remained some months in Egypt, leaving Cleopatra pregnant with Caesarion (later Ptolemy XV) generally acknowledged to be Caesar's son.

Caesar's excursion to Egypt was to have lasting consequences for the independence of the country. Long subject to Roman influence, Egypt became a province of the Empire when Octavian (Augustus) occupied the country after the defeat of Marcus Antonius at Actium and the suicide of Cleopatra in 30 BC.