From the very earliest times the Kings of Rome co-founded their right to rule with their divine ancestry. Romulus was son of a Vestal Virgin and the god Mars whilst his successor Numa had a private entente with the goddess-nymph Egeria who used to whisper to him what to do next with the government and politics of Rome. Julius Caesar was no fool either and politics led him to align himself with Venus, probably to give himself an excuse for being uncontrollably promiscuous!
Wherever possible the gods and (propitious) destiny were closely related with one’s own family and stars and hence with one’s own birth sign. Julius Caesar and his heir Augustus aligned their Julio-Claudian dynasty with the protecting influence of Mars and Venus. This wasn’t possible for all Roman citizens but those who achieved the highest power clearly did their best to justify it as a divine right.
An interesting example of this propagandistic battle of the gods is found during the struggle for supreme power between Octavian (Augustus) and Marc Anthony, following the death of Julius Caesar. Marc Anthony at first aligned himself and actually took on a vague visual semblance to Hercules from whom his family was said to descend. Following his increasingly passionate affair with Cleopatra and Egyptian culture, Marc Anthony realigned his public image with that of the festive, possibly chaotic god Dionysus/Bacchus. Augustus chose to align his public image with the direct opposite divinity: Apollo, god of order. After the struggle Augustus realigned his divine politics with Mars.