What were the responsibilities of the king who is the state to his people? What makes a king "a good king" in Beowulf?
One phrase that occurs throughout the epic is “He was a good king.”
The epic poem Beowulf begins as an honor to the ideal, Christian King Beowulf:
LO, praise of the prowess of people-kings
of spear-armed Danes, ...
a good king he!
To him an heir was afterward born,
a son in his halls, whom heaven sent
to favor the folk, feeling their woe
that erst they had lacked an earl for leader
so long a while; the Lord endowed him,
the Wielder of Wonder, with world's renown.
Famed was this Beowulf: far flew the boast of him,
son of Scyld, in the Scandian lands.
So becomes it a youth to quit him well
with his father's friends, by fee and gift,
that to aid him, aged, in after days,
come warriors willing, should war draw nigh,
liegemen loyal: by lauded deeds
shall an earl have honor in every clan.
So, a good King, is Christian (willing to die for his people); represents skill and courage in battle; makes an indelible name (mark) for himself; exhibits loyalty ("Comitatus" to his lord) as a code of allegiance; shows royal generosity (shares his boon and bounty); enacts revenge against his enemies (wegild: "manprice"); and achieves enduring fame as carried by the scop (bard) orally:
(On their lord beloved they laid no slight,
gracious Hrothgar: a good king he!)
From time to time, the tried-in-battle
their gray steeds set to gallop amain,
and ran a race when the road seemed fair.
From time to time, a thane of the king,
who had made many vaunts, and was mindful of verses,
stored with sagas and songs of old,
bound word to word in well-knit rime,
welded his lay; this warrior soon
of Beowulf's quest right cleverly sang,
and artfully added an excellent tale,
Remember, too, that Beowulf is the archetypal epic hero, one who embodies all the most valued characteristics of Anglo-Saxon society. All his actions throughout the course of the epic could therefore be viewed as exemplary and even a guideline of sorts for kings in that time and society.
When you look at what Beowulf accomplishes, you can learn a great deal about what his society expected from a king. For example, he took the lead in fighting Grendel, even disdaining the use of weapons since Grendel was unarmed (pun not intended). So he demonstrates the bravery that was required of all leaders.
He also manifests loyalty to Hrothgar, since Hrothgar had once helped Beowulf's father. Beowulf feels obligated to help Hrothgar as a show of loyalty to someone who had previously aided his own family. A good king would show loyalty, proving he could be relied upon as well.
Beowulf was generous to a fault as well. At the end of his life, as an old man, he is willing to confront the dragon to protect his people, not because he wants to treasure for his own personal gain, but to give to his people and protect them from the dragon's ire at the same time.
All these characteristics make Beowulf a "good king" in the eyes of his society then, and even in society's view today.