Professionally, Caesar had placed Cleopatra on the throne. For many years Egypt had been beset by civil war, and before Caesar intervened, Princess Cleopatra was at war with her little brother/ husband, Ptolemy XIII, who was in his early teens and a puppet ruler as a result. At the same time, Rome too was engaged in civil war, and after the Battle of Pharsalus, the great deciding battle of this war, the Republican leader Pompey came to Egypt, hoping for asylum from the king. This was not forthcoming; Pompey was murdered by Lucius Septimius and Achillas, two commanders in Ptolemy's army, and his head was presented to Caesar when he came to Egypt as a legate following this murder. They had assumed Caesar would be pleased to see his rival dead, and presenting an enemy's head on a platter was a common custom among Eastern rulers - all this simply served to offend Caesar, however, and put the king on very bad terms with him. Shortly after his arrival in Egypt, Cleopatra arrived in Alexandria, smuggled inside a rolled-up carpet, which was unfurled in front of Caesar to reveal the princess inside. Caesar was notoriously amorous, so the surprise of a sensual young princess had quite the effect on him. He went on to support Cleopatra's claim to the throne, winning a number of battles on her behalf, and then left her to rule as undisputed Queen of Egypt.

Their personal relationship was no doubt a very intimate one - there's no reason to believe Caesar and Cleopatra weren't lovers; both of them recognised that the other was a useful ally to have, and both of them were well-known for being highly charming and passionate individuals. Cleopatra made visits to Caesar at Rome and even tried to attend his funeral, but was forbidden from doing so by Caesar's killers. As for the identity of her son, Caesarion's father, there's no reason to doubt he was Caesar's son, but no reason to believe it outright either. But it's clear that the two were on very good terms with each other!

During the reign of Cleopatra Egypt was two things. Rich and weak. The grain from the Nile region made the country incredibly wealthy and the Romans were forced to pay through for said grain to feed the city of Rome itself. Egypt was further surrounded by Rome on both sides. It would seem likely that the Romans would try to incorporate Egypt into the empire. Added to this the ruling Ptolemaic dynasty which had ruled Egypt since the death of Alexander was quite unpopular. They essentially remained Greeks ruling over a subject populace. It is telling that one of the first steps that Cleopatra took was to learn Egyptian, she was the first Ptolemaic Pharaoh to do so, as a way of strengthening her rule both against the Romans and her brothers with who she ruled jointly.

As a woman it seemed logical to her to use all the tools that she had available to her to ensure that Egypt remained interdependent and that she would keep her throne against her brother. In this way we might say that her seduction of Caesar was no more than a political expedient, as was her later seduction of Mark Antony. He was certainly at this point the most powerful man in the Mediterranean world at this time. I do not know to what extent Caesar and Cleopatra were actually in love, she certainly bore him a son and he put up a golden statue of her in the forum. We can surmise that there certainly was some emotional connection between the two but in my opinion Cleopatra was always using Caesar for the political security that came with him, not because she was madly in love with him.