It is hard to take out the truth from the illusions. Cassius Dio had told her story and enclosed it as he says "She captivated the two greatest Romans of her day, and because of the third she destroyed herself."
When Cleopatra was eighteen years old, she got married to son of Ptolemy who was only nine years old at that time. Cleopatra was an intelligent and power oriented girl. She wanted to rule the throne all by herself. She tried to rule alone and if not alone, at least not equivalent to her brother. Cleopatra's rule was over thrown by the ministers in 48 BCE. In the mean time Pompey came to Egypt while he was being chased by forces of Julius Caesar1.
Pompey was killed by Ptolemy XIII. Cleopatra's sister and Ptolemy XIII affirmed herself ruler as Arsinoe IV2. Cleopatra had to win the support of Julius Caesar's, the fasanating stories tell that she wrapped her self in a jewel carpet and presented herself to him. In a fight with Caesar, Ptolemy XIII died, and Caesar returned Cleopatra to power in Egypt and her brother Ptolemy XIV came in as a co-ruler. Cleopatra had a son in 46 BCE, Cleopatra gave her newborn son, the name Ptolemy Caesarion. She claimed that he was Julius Caesar's son and that she was married to him.