In August 991 Byrhtnoth, ealdorman of Essex, encountered an army of vikings camped on Northey Island in the estuary of the River Blackwater near the town of Maldon, Essex. This island was (as it still is) connected to the mainland by a causeway which was covered at high tide. As the causeway was flooded when the armies met, battle could not be joined; when the tide went out, uncovering the causeway, the English were able to keep the vikings bottled up on the island. Then, in a notable tactical blunder, Byrhtnoth decided to allow the viking army to cross to the mainland, presumably so as to break the stalemate. In the battle that followed, Byrhthnoth was slain, much of his army routed, and many (perhaps most) of those who remained slaughtered.
The Battle of Maldon, which commemorates this disaster, is one of a number of poems that find inspiration in defeat: others include The Song of Roland, a fictionalized account of the annihilation of a Frankish army by Saracens; a number of Serbian epics, which dwell upon the fourteenth-century defeat of the Serbs at the Battle of Kosovo and their subsequent domination by the Ottomans; and of course Tennyson's Charge of the Light Brigade, written on the occasion of one of the most famous military disasters in English history. The poetry of defeat, in giving voice to a nation's grief, can stir nationalist sentiment and rouse soldiers to deeds of valour (Tennyson's poem, famously, was distributed in pamphlet form to soldiers in the Crimea). It can also express nostalgia for the values of a supposedly greater national past. The Battle of Maldon does all these things. The anonymous poet is largely uninterested either in demonizing the vikings or in the violence of the scene, and his treatment of the cowards who run away is cursory. Rather, he focuses intensely on the thoughts and words of the men who stay, often juxtaposing their own resolute statements with foreshadowings or spare notices of their deaths. These doomed warriors are predominantly young (one of the most common words that describe them is hyse 'young man'): and yet they cast their lot with the aged Byrhtwold, whose sole remaining wish is to lie by the side of his lord. Even as defeat grows more certain, they hold their ground or, more often, advance. Indeed, forð 'forth, forward' is the poem's most prominent adverb, being used ten times of the English troops. But forð is also associated with death in Old English: in The Wanderer (81), death is forðweġ 'the way forward', while in The Dream of the Rood (132-3) the narrator laments that his friends forð ġewiton 'have gone forward' into death; and the most common euphemism meaning 'to die' is forðfēran 'go forth', attested hundreds of times in the Anglo-Saxon Chronicle and elsewhere. The young warriors who go forð to the next life subscribe to the code of absolute loyalty to one's lord described as early as the second century by the Roman historian Tacitus and celebrated in the Anglo-Saxon Chronicle entry for 755 (see 'Cynewulf and Cyneheard', no. 3 above). As English fortunes declined during the decades following 991, partly because of English treachery, this code of loyalty must have seemed more and more to be a thing of the past.
The poem was already fragmentary, its opening and closing lines lost, when the unique manuscript was destroyed in the Cotton Library fire of 1731. Fortunately a transript had been made by Deputy-Librarian David Casley; all subsequent editions are based on this transcript. The standard recent edition is Scragg [xx]; the editions in Pope and Fulk (19xx) and Mitchell and Robinson [xx] are also valuable. For a collection of useful studies of the battle and its context, see Scragg [xx].
The language of this poem is late and fairly easy. You should be aware that the ending -um sometimes appears as -on or -an and that there is no formal distinction between indicative and subjunctive in the past plural.