"a fair vestal, throned by the west"

Oberon's description of how the flower "love-in-idleness" was made magical (II i 148-) may refer to an elaborate court masque held a year or two prior to the first performance of A Midsummer Night's Dream. Whether this is the case or not the "fair vestal" spoken of in these lines (II i 159) is most likely a royal compliment to the Virgin Queen, Elizabeth I.