To begin, the concept of a servant leader needs defining. A servant leader, the term and practice coined by Robert Greenleaf, refers to the idea that people share power. This concept allows the needs and success of others comes before the needs and success of the individual (not speaking to the disinterest in the health of the self, but that one should put others first). This practice has currently become popular given the success of Stephen Covey's The Leader in Me, his collection of Seven Habits, and character education.
Within Grenleaf's ideologies, he named ten characteristics necessary of the servant leader: listening, empathy, healing, awareness, persuasion, conceptualization, foresight, stewardship, commitment to growth, and building a community.
As for the character of Beowulf (from the epic of Beowulf), he could very well be identified as a servant leader. He listens to the stories of Grendel attacking Heorot, empathizes with Hrothgar, and goes to heal the pain and suffering brought on by the demon. Beowulf is aware that Grendel is a powerful foe and promises that he will fight without weaponry in order to uphold and maintain his aristeia and arete (excellence in battle). Beowulf persuades his men and Hrothgar that to fight without weapons is the best. Beowulf conceptualizes that he may lose (if it is within God's will). He understands that the Anglo-Saxon life is filled with uncertainty and based upon wyrd (fate).
Beowulf understands (foresight) how the past, present, and future are all intertwined (given his attention to the histories provided by Hrothgar--in an effort to insure Beowulf always walks in the path of light). He acts as a steward when he asks for his rewards to be sent back to his home if he is killed during his fight with Grendel's mother. H's fifty years as king proves his commitment to the growth of his people (no one ever wished to fight him and his people stayed safe). Lastly, his great nature proves to his people the importance of caring for one another and their community at large.