The appearance of Grendel’s mother in Beowulf is described, at first, in terms which seem to underplay her strength when compared to the masculine capabilities of her son. However, a close reading of the poem shows evidence that Grendel’s mother is more dangerous to the men of Heorot than Grendel himself was. Such a reading seeks to destabilise the ready leap that assume feminine weakness from a surface-level acceptance of the text’s comments on feminine strength.
After her introduction, the narrator describes Grendel’s mother’s assault as being “less only by as much as an amazon warrior’s strength is less than an armed man’s when the hefted sword… razes the sturdy boar-ridge off a helmet” (Heaney ll. 1284-1287). This reading seems to imply that, to the observer, there is no visible difference in the ferocity of the onslaught (for the result is the same), only in the image of the attacker. Though the arm that wields the analogous blade may be feminine instead of masculine, the ridge is razed nevertheless.
Admittedly, some circumstances in the assault complicate this reading: Grendel’s mother is seized with “mortal terror the moment she was found” (ll. 1293). This is in stark contrast to Grendel, whose dominion in Heorot exists in fearless despite of the men who would resist him: “So Grendel ruled in defiance of right, one against all […] He took over Heorot, haunted the glittering hall after dark” (ll. 144, 166-167). The differences in their attacks uncover the comparative tension between the masculine and feminine assaults, for although Grendel’s first attack is a hit-and-run raid just as his mother’s is, there seems to be an immediate difference in scope (Grendel carries off thirty men; his mother, but one). Looking beyond this first impression of simple numerical supremacy, Grendel’s mother is described as having chosen a target of incomparable value: “She had pounced and taken one of the retainers… To Hrothgar, this man was the most beloved of the friends he trusted between the two seas” (ll. 1294-1297). In addition, “She had snatched their trophy, Grendel’s bloodied hand,” at a stroke unravelling the visual evidence of Grendel’s defeat, thus rendering Beowulf incapable of physically establishing his triumph over her son (ll. 1302-1303).
In the battle between Beowulf and Grendel’s mother, Grendel’s mother is strong enough that “the shining blade refused to bite” (ll. 1523-1524). His strength alone is insufficient as well; it takes “a sword in her armoury” to deal the final blow, and to return the evidence of Grendel’s defeat—his head—to the vanquisher, Beowulf. Finally, then, it is only through the weapons of the monstrous female that she can be defeated.