Theseus gained Hippolyta as his soon-to-be bride by capturing her in battle. As queen of the Amazons, she was not used to bending to patriarchal authority. However, she seems at this point in the play to have acquiesced gracefully to her fate.
Theseus notes the violent way he gained her "love," but promises her that
I will wed thee in another key,
With pomp, with triumph, and with reveling.
In other words, rather than a battle (as before), the wedding day will be joyful, peaceful, and festive, Theseus states.
However, if we look closely at the wording, it seems as if Theseus is also envisioning his wedding in terms of a Roman triumphal march, where he is showing off the spoils of war. In this case, these "spoils" would be Hippolyta. The words "pomp," "triumph," and "reveling" bring to mind a parade and military celebration. It would appear that Theseus is still thinking of his new bride as a trophy or conquest. This is one type of love in a play that examines many varieties of love's lunacy.