Theseus' history is merely alluded to in A Midsummer Night's Dream. Titania and Oberon mention his amorous interludes with various women (II i 70-80), and he speaks himself of how his amazonian bride Hippolyta is a war prize (I i 16-17). His mythological background would have been known to Shakespeare and probably to some of his audience. [more]
The seductive and destructive powers of women figure centrally in Theseus' career; and his habitual victimisation of women, the chronicle of his rapes and disastrous marriages, is a discourse of anxious misogyny which persists as an echo within Shakespeare's text, no matter how much it has been muted or transformed. (Montrose 1996: 118)
An added irony of Theseus' mythological history is that the son he and Hippolyta would have together came to a tragic end, and certainly did not fulfil Titania and Oberon's ritual blessings and hope for future offspring of the lovers in V i 376-408.
See background material on Theseus in the Encyclopedia Britannica.