decays > downfalls; deaths

6 Their swords and spears were broken, and hauberks rent;

hauberk > {Chain-mail tunic; chain-mail covering for neck and shoulders} rent > torn

7 And their proud garlands of triumphant bays

bays > {Leaves or sprigs of the laurel, used to make a wreath for conquerors}

8 Trodden in dust with fury insolent,

insolent > immoderate; overbearing; or: exultant (SUS: cf. CC 622)

9 To show the victor's might and merciless intent.

intent > frame of mind; intention

311.53