Determine the rhyme scheme of the following poem.
XXVII (From Fairie Queene)
by Edmund Spenser
Not that great Champion of the antique world,
Whom famous Poetes verse so much doth vaunt,
And hath for twelve huge labours high extold,
So many furies and sharpe fits did haunt,
When him the poysond garment did enchaunt,
With Centaures bloud and bloudie verses charm'd;
As did this knight twelve thousand dolours daunt,
Whom fyrie steele now burnt, that earst him arm'd,
That erst him goodly arm'd,
now most of all him harm'd.