So every elder and experienced councilman
among my people supported my resolve
to come here to you, King Hrothgar,
because all knew of my awesome strength.
They had seen me boltered in the blood of enemies
when I battled and bound five beasts,
raided a troll-next and in the night-sea
slaughtered sea-brutes. I have suffered extremes
and avenged the Geats (their enemies brought it
upon themselves, I devastated them).
Now I mean to be a match for Grendel,
settle the outcome in single combat.

Beowulf, Seamus Heaney (trans.)

Lines 415-426: Beowulf describes who he is to King Hrothgar by recounting his deeds.