Sir Gawain shocked the crowd by accepting the challenge to fight the Green Knight. Clearly, the Green Knight was a warrior with much more experience than Gawain. Most of the individuals in the crowd believed that the Green Knight would easily subdue Gawain. Summoning his strength, Sir Gawain raised his sword and prepared to do battle with the Green Knight.

In the passage, which does subdue mean?
to do battle with
to defeat
to chase away