Queen of the Amazons, and daughter of Mars. Shakespeare has introduced the character in his Midsummer Night's Dream, where he betroths her to Theseus, Duke of Athens. In classic fable it is her sister Antiope who married Theseus, although some writers justify Shakespeare's account. Hippolyta was famous for a girdle given her by her father, and it was one of the twelve labours of Hercules to possess himself of this prize.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894