What is the meaning of 'called for quarter' in this phrase from Charles Dickens, The Old Curiosity Shop, Chapter 6?
With which defiances the dwarf flourished his cudgel, and dancing round the combatants and treading upon them and skipping over them, in a kind of frenzy, laid about him, now on one and now on the other, in a most desperate manner, always aiming at their heads and dealing such blows as none but the veriest little savage would have inflicted. This being warmer work than they had calculated upon, speedily cooled the courage of the belligerents, who scrambled to their feet and called for quarter.”