There are several versions of the birth of Venus: according to one, she was the daughter of Jupiter-Zeus and Dione; in another, she was born from the foam that arose when Chronos (Saturn) castrated Ouranos (Uranus) and flung his genitals into the sea.
Venus was above all the goddess of love and feminine beauty. She was also the patroness of marriage and fertility. Ancient authors often distinguished several personifications of Venus-Aphrodite: the philosopher Plato contrasted heavenly Aphrodite, the goddess of pure, chaste love, with the popular Aphrodite, patroness of sensual, physical love.
In addition to this main attribute, Venus seems to have had many secondary ones, with a specific epithet for each: being born of the foam, she was also the goddess of the sea and navigation ("Venus Marina"); and sometimes she was characterised as victorious (or Victrix) and was invoked in battle.
Venus played a particular role in the eyes of the Romans of the Ist century BC: Julius Caesar claimed that his family (the Julii) descended from this goddess, through Aeneas. Venus was therefore considered the appointed patroness of this illustrious family, and was lavishly worshipped by Caesar (who built a temple in his forum to Venus Genetrix) and his successors.