King Hrothgar's despair over the inability to defeat Grendel. Is the scene from Beowulf reading that is an example of internal conflict.
Internal conflict in literature is the struggle occurring within a character's mind. The struggle comes about when things the character vies for can't be reached in reality.
In Beowulf, the character with internal conflict is King Hrothgar. He is internally conflicted because he vies for the death of Grendel but he his strategies of killing Grendel all failed. Thus, his goal can't be reached.