<P> Beowulf begins with the story of Hrothgar, who constructed the great hall Heorot for himself and his warriors . In it, he, his wife Wealhtheow, and his warriors spend their time singing and celebrating . Grendel, a troll - like monster said to be descended from the biblical Cain, is pained by the sounds of joy . Grendel attacks the hall and kills and devours many of Hrothgar's warriors while they sleep . Hrothgar and his people, helpless against Grendel, abandon Heorot . </P> <P> Beowulf, a young warrior from Geatland, hears of Hrothgar's troubles and with his king's permission leaves his homeland to assist Hrothgar . </P> <P> Beowulf and his men spend the night in Heorot . Beowulf refuses to use any weapon because he holds himself to be the equal of Grendel . When Grendel enters the hall, Beowulf, who has been feigning sleep, leaps up to clench Grendel's hand . Grendel and Beowulf battle each other violently . Beowulf's retainers draw their swords and rush to his aid, but their blades cannot pierce Grendel's skin . Finally, Beowulf tears Grendel's arm from his body at the shoulder and Grendel runs to his home in the marshes where he dies . Beowulf displays "the whole of Grendel's shoulder and arm, his awesome grasp" for all to see at Heorot . This display would fuel Grendel's mother's anger in revenge . </P> <P> The next night, after celebrating Grendel's defeat, Hrothgar and his men sleep in Heorot . Grendel's mother, angry that her son has been killed, sets out to get revenge . "Beowulf was elsewhere . Earlier, after the award of treasure, The Geat had been given another lodging"; his assistance would be absent in this battle . Grendel's mother violently kills Æschere, who is Hrothgar's most loyal fighter, and escapes . </P>

Where did the battle between beowulf and grendel take place