Why did Romans use Troy for their political purposes?

Since the third century B. C. E., the Roman Empire had accepted Troy as its source of origin. The reason for this was the belief that Venus/Aphrodite saw to the escape of the only surviving Trojan hero Aeneas and his mother to Italy and their settling down there as the ancestors of Romans. This goddess is at the same time the goddess of Caesar, who influenced the politics between 60-44 B.C. E. While there is no concrete evidence for this belief, the Ilius Dynasty put forth that they came from the ancestry of Aineias's son Ilius (or Iulus) in order to reinforce their claims to royalty. Shortly before he was assassinated, Caesar was preparing an extensive expedition against the Parthians; following the footsteps of Alexander the Great. According to some historians, he had planned to move the capital of his new empire to the old land of Troy, but this plan was cut short by his assassination. His predecessor Augustus (30 Β.C.E.-14C.E.) had also entertained ideas such as this and was warned by the Roman poet Horatio with these words:

"As long as the sea moves back and forth between Rome and Ilion, the Roman Empire will last."

Emperor Augustus also supported his "ancestors' land" Troy/Ilion. With the help of the Aeneas epic that he asked his poet Virgil to write, Augustus moved this imaginary historical piece of fiction to reality and in some way legitimized this event.