This terror of the hall-troops had come far.
A foundling to start with, he would flourish later on
as his powers waxed and his worth was proved.
In the end each clan on the outlying coasts
beyond the whale-road had to yield to him
and begin to pay tribute. That was one good king.

These warrior values insist that a good king was one who terrorized other tribes. This prologue is used to contextualize Hrothgar's kingship, gained through favors of warfare and careful cultivation of loyalty among his followers. Hrothgar's success leads him to build the mead hall that makes him and the Danes a target for other marauders, notably Grendel.

The sorrows of Hrothgar are presented as part of the cycle of good and bad fortune people experience in life. Neither Hrothgar nor the Danes are at fault for the tragedy Grendel represents, nor are they capable of defending themselves against a supernatural evil. Grendel is not a normal opponent for whom normal acts of bravery battle are sufficient. Beowulf is brave and loyal in coming to Hrothgar's aide. but his is presented as the one warrior among countless capable of helping the Danes. Just as Hrothgar's powers are waning, Beowulf's are waxing.

When we move to the end of the poem and to the dragon episode, we need to change our expectation of Beowulf's responsibilities. Like Hrothgar, the old Beowulf is troubled by an unnatural attack on his people, and no one seems capable of restoring order. Beowulf eventually goes into battle against this dragon, yet his warriors mostly hang back, afraid to enter the fray. Only after Beowulf has been mortally wounded does Wiglif step forward in loyal defense of his king, indicating his rightfulness to take over as leader of the Geats. The poem ends with premonitions of the Geats being attacked once word gets out that they are without their powerful king. Women keen in grief, and the anticipation of grief and endless sorrow as they observe Beowulf's funeral rights. Their sorrow is not just over the loss of a great king but also over what it means to be without strong protection from other tribes who will crave the gold the Geats had taken from others.

The question we need to ask here then is whether this last decision Beowulf makes is the mark of a good king or whether Beowulf misunderstands his role and remains locked in the warrior code. One could argue for either side, but the poem's ending has a complexity that minimizes and reductive "superhero" understanding. Had Beowulf not fought the dragon but had cultivated greater bravery among his warriors, might he have lived to protect the Geats until a new king could take over? Does he doom the Geats because he refuses to stay within the role of king, preferring instead the glory a warrior earns? Or, is his death and the eventual destruction of the Geats by neighboring tribes whom the Geats have defeated merely a grim reminder of the fragility of safety and comfort in a world defined by aggression?

It seems that one must celebrate Beowulf as a warrior, among whom he is undeniably the best. His kingship, however, is less clear. He is a good king because by the standards his Anglo-Saxon culture fosters he does what the comitatus instructs, but he may not be a great king. At the same time, the apparently later Christian touches in the poem suggest that God gives a limited period of glory and power to humans but forces of profound evil (descended from Cain) will always threaten humans, especially in their pagan existence.

The characteristics of a good king, according the epic poem Beowulf, parallel the characteristics honored by the Anglo Saxon culture.

Anglo Saxons looked for their heroes, and therefore kings, to be great warriors, eloquent speakers, and renowned leaders. They should be of noble ancestry. Anglo Saxons also looked to their heroes to be generous, exemplify aristeia (battles should be of the finest and most noble challenging foes of only equal or greater ability), seek fame and fortune, and hold up arete (the bringing of virtue to perfection), and (of course) be courageous and strong.

The Anglo Saxons honored their kings with titles for the same reasons they honored their heroes with titles.

Chapter thirty-seven of Beowulf defines what the epic hero believes to be the characteristics of a good king. Beowulf tells Wiglaf, upon his death bed, what a good king will do (or does). 

“There was...none at all, who would bring war-mates against me and threaten me with horrors. I observed social custom in my home, and cared for my own with justice. I did not seek feuds, nor have I falsely sworn any oath...[and] I did not kill my kinsmen!"

It is in this paragraph that Beowulf defines the very specific characteristics of a good king. 

1) No other kings tried to bring war against Beowulf or his kingdom. 

2) Beowulf, as a good king, was always true to the customs of the Danes. 

3) Beowulf, as a good king, was just (correct and lawful) in his laws.

4) A good king makes no promises he cannot keep and does not seek out battles (feuds). 

5) Beowulf, as a good king, never killed any of his own people or family. 

Beowulf's fatal flaw is usually identified as "ofermod," or overconfidence. It is this flaw which leads him, in the third act of the poem, to confuse being a good warrior with being a good king. While military strength was expected of a king in Anglo-Saxon culture, and kings were certainly expected to be able to defend their people against invasion, Beowulf shows a failure to understand delegation and the different phases of a man's life when he chooses to take on the dragon himself, despite being beyond his prime fighting years. In tackling the dragon, Beowulf's desire to maintain his reputation as a warrior leads to his people being left without a king.

Compare Beowulf to Hrothgar: an older man, Hrothgar's principal concern is with protecting his people, just as Beowulf's is at the end of the poem. Hrothgar is depicted as an ideal king, a man who was once strong militarily and who has the wisdom and power to rule. However, in defending his realm from Grendel, he does not endanger himself and put his people in the situation of having to cope without a king. Instead, it is the young warrior, Beowulf, who protects Hrothgar's people from Grendel. At this point in Beowulf's life, this is an appropriate use of his skills. In order to truly be a model king in later life, we might infer, Beowulf too should have turned to a younger man at a different stage of life to defend his people from the dragon threat, rather than endangering them politically by privileging the warrior side of himself over the part of him that rules as king. Beowulf wants to be remembered as a great warrior, rather than as a great king, which, in itself, identifies why he is an example of the former rather than the latter.

In the time in which Beowulf was first told (it had been handed down in the oral tradition long before it was ever written down), survival was something the men and women of the day dealt with constantly: it was as common as taking a breath.

Those individuals who survived would have been strong warriors; and in the Anglo-Saxon world, this applied to men and women who fought side-by-side.  Being a great warrior, however, spoke to individual survival, not necessarily to that of a group. A community could only survive with the collective skills of its warriors. And as great warriors were valued among the members of this civilization, it was the strongest and wisest warrior who would be king.

True enough, there would be leaders who ruled only by strength and force of will, but in Beowulf, the king was a man who commanded respect because of his wisdom, courage and integrity.  These were the characteristics that would command the allegiance of the strongest of warriors.  Many men could be excellent warriors, but not every warrior could be a king.

Beowulf had served such a king during the time he was proving himself on the battlefield--showing himself to be a man of great valor.  Marital experience was only one aspect of Beowulf's character, but coupled with his just and fair-minded treatment of others, he won the respect and regard of his society, and he ultimately became the king of his people.

Being the strongest warrior held an important place within this coarse and primitive culture, but the qualities of a leader went well beyond strength, and looked to the character of the man and his ability to guide his people in the best and worst of times.

In the Old English poem Beowulf, both Hrothgar and Beowulf are portrayed as morally fair, noble, and brave. These are qualities befitting good kingship in this old warrior society. They, therefore, affirm the standards of Germanic heroic poetry.

When a warrior (the thane) pledged obedience to his lord, their relationship would be one that relied chiefly on mutual respect and male fidelity. The thane would be an honorable voluntary companion who would pride himself on supporting his lord in war. In response, the lord would repay his valor with lavish material goods. It is made apparent in the epic that Hrothgar is "the helmet of Shieldings" (l. 456, Seamus Heaney translation). This would be a marker of his formidable kingship. Material emblems would also perform like a signpost of the warrior's glory as well as the king's generosity. Therefore, a good king would be identified as the upright 'ring-giver' or noble 'shield' of his nation, hence Hrothgar's lofty reputation.

If one of the king's men had been slain in battle, a warrior had a moral duty to exact a just vengeance (a compensation through revenge-slaying). In Beowulf, Hrothgar's friend Aeschere is killed by Grendel's mother in a vengeful attack. Out of respect for the forlorn old king, it is imperative that Beowulf invoke this code of retribution. To young Beowulf, "it is always better / to avenge dear ones than to indulge in mourning" (ll. 1384-85). It is this ideology that motivates him to slay Grendel's mother. Beowulf becomes a paragon of heroic power. He is indifferent to death if he can ably defend his nation. In return for this, Hrothgar furnishes the heroic Beowulf with "twelve treasures" (l. 1867).

Valor is also inseparable from good kingship:

Thus Beowulf bore himself with valor;
he was formidable in battle yet behaved with honor
and took no advantage. (ll. 2177-79)

When Beowulf subsequently ascends the throne, he performs with great valor despite his old age:

I risked my life
often when I was young. Now I am old,
but as king of the people I shall pursue this fight
for the glory of winning. (ll. 2511-14)

He may be an opportunist who craves majesty and fame, yet his sacrifice is a fine marker of his nobility. It is unsurprising that the Geat people recall,

of all the kings upon earth
he was the man most gracious and fair-minded,
kindest to his people and keenest to win fame. (ll. 3180-82)

From reading Beowulf, I think that the attributes that made a good king in Beowulf's time are almost as mythical today as is our hero, Beowulf.

In comparing the two kings in the story, we must study Hrothgar and Beowulf. Hrothgar is the leader of the Danes. He is admired for his bravery and his honor. He values the lives of his people, and will do whatever he can to protect them. He admires other men of valor and is appreciative of the help Beowulf offers:

...he adopts Beowulf "in his heart" as a son. [A great] tribute...[coming] from the mouth of a king.

Hrothgar is wise, a man of God, and one not afraid to show his emotions in public which is not seen as a weakness of that time, but simply one side of Hrothgar's nobility.

Beowulf shows the reader early on that he is a man of valor and honor. He is not as interested in what he may gain personally from his actions as he is in finding how he might be of service to others. In fighting Grendel, his desire is to aid the Danes, and bring glory to his feudal lord. He has concern for the lives of others and is willing to sacrifice his health and life to serve the needs of those in Hrothgar's kindgom. Beowulf is a man of God; his faith is strong and he recognizes that his successes depend on the will of God.

These characteristics follow Beowulf through the fifty year until he also becomes King of the Geats.

Beowulf's valor, hereditary pride and faith are not restricted to the days of his youth.

Even though he is now much older, he still exhibits the same valor of his younger days, and welcomes the opportunity to defend his people from the wrath of the "firedrake," even if he loses his own life. He also is a king who cares deeply for his people and is willing to sacrifice himself for the welfare of others. In death, he is still considered a "gracious and fair-minded" king.

In summary, a good king in the time of the story of Beowulf was a man who was honorable, loyal, wise, fair, someone of strong Christian faith, and someone concerned for his people—willing to do whatever was necessary for the good of others. His own welfare was not as important as his need to be of service to those in need: he was one willing to make sacrifices.

Beowulf is a good king, but a better warrior. He is the finest example we have in the poem of both roles. Indeed, it is clear that being a great king entails being a great warrior in the society of the Geats and the Danes. Hrothgar has failed in the respect of being a great warrior. He was once a great warrior, but now he can no longer protect his people. His weakness forces him to rely on Beowulf to provide security.

At the beginning of the poem, Beowulf fulfils all the criteria for a great warrior and epic hero. He is young and nobly born. He is supremely strong and brave. He actively seeks out the opportunity for glory. Even his boastfulness and arrogance in brandishing Grendel's arm as a trophy are in the tradition of the great warrior. Achilles would undoubtedly have done the same.

We do not know the details of Beowulf's long and peaceful rule over Geatland, only that he dies protecting the Geats from a dragon. It appears that, even at an advanced age, he is still the bravest warrior among the Geats. Only Wiglaf is even brave enough to stand beside him. After his death, the mourning of the Geats is somewhat selfish and cowardly in tone. They are afraid that, without Beowulf to protect them, they will be vulnerable to attack by surrounding tribes. It is clear, therefore, that Beowulf's effectiveness as a king always rested on his prowess as a warrior. He has been a good king principally because he was the greatest, most feared, and most esteemed warrior of his age.

In many ways, this text concerns not just the heroic exploits of Beowulf but also the debate of what makes a good leader. This is highlighted through a repeated refrain that occurs from the very beginning of the text: "That was one good king." The text includes various references to other good leaders, whose example is held up as being worthy of making them a good leader. Note the following reference to the early Danish king, Beow, who was another example of a "good king":

And a young prince must be prudent like that,
giving freely while his father lives
so that afterwards in age when fighting starts
steadfast companions will stand by him
and hold the line. Behaviour that’s admired
is the path to power among people everywhere.

This reference is made by Hrothgar, who is himself presented as the model of a good leader. It also highlights his pragmatic prudence, as in the warrior code it was expected that generosity would be a key feature of leaders in order to secure loyalty. Although this quote targets generosity as being one particular characteristic that a good leader must have, at the same time, it also highlights an important principle about leadership, which is that good leadership is built on actions rather than words alone. This becomes immensely important when Beowulf is compared with Unferth. Beowulf, although he boasts about his bravery and skill, shows the truth of his words through his actions in fighting Grendel. Unferth, on the other hand, is exposed to be nothing more than a big talker who does not support what he says through his actions. A good leader ultimately therefore is somebody who is defined by action rather than just talk, as both Beowulf and Hrothgar demonstrate.