Question: What book contains a poem which, along with "Beowulf" and the "Anglo-Saxon Chronicle", preserves a legendary list of the kings of the Angles?

Context paragraphs:
Frithwald: Frithwald (Old English: "Friþuweald" or "Friðewald"; d. 762 × 764) was an Anglo-Saxon Bishop of Whithorn.  The version of the "Anglo-Saxon Chronicle" in the "Worcester Chronicle" says that in 735 he succeeded Pehthelm, after the latter's death, as Bishop of Whithorn.  The only other source for Frithwald is the entry in versions D and E of the "Anglo-Saxon Chronicle" which, "sub anno" 762, relate that:Frithwald, bishop at Whithorn, died on the Nones of May [May 7].  He was consecrated at Chester on the eighteenth before the Kalends of September [August 15], in the sixth winter of Ceolwulf's kingship [734/5]; and he was bishop twenty-nine winters<br>"Friþuweald biscop æt Hwiterne forðferde on Nonas Maius, se wæs gehalgod on Ceastre on . xviii.  Kalendas September þam . vi.  wintra Ceolwulfes rices, 7 he wæs biscop . xxix.  wintra".  If the Worcester source is correct, that would put his death in 764; the entry is also sometimes thought to cover the year 763.

Kings of the Angles: The Angles were a dominant Germanic tribe in the Anglo-Saxon settlement of Britain, and gave their name to the English, England and to the region of East Anglia.  Originally from Angeln, present-day Schleswig-Holstein, a legendary list of their kings has been preserved in the heroic poems "Widsith" and "Beowulf", and the "Anglo-Saxon Chronicle".

The Dragon (Beowulf): The final act of the Anglo-Saxon poem "Beowulf" is about the hero Beowulf's fight with a dragon, the third monster he encounters in the epic.  On his return from Heorot, where he killed Grendel and Grendel's mother, Beowulf becomes king of the Geats and rules peacefully for fifty winters until a slave awakens and angers a dragon by stealing a jewelled cup from its lair in order to gain freedom from killing his brother.  When the angry dragon mercilessly burns the Geats' homes and lands, Beowulf decides to fight and kill the monster personally.  He and his thanes climb to the dragon's lair where, upon seeing the beast, the thanes flee in terror, leaving only Wiglaf to battle at Beowulf's side.  When the dragon wounds Beowulf fatally, Wiglaf slays it.

Battle of Brunanburh (poem): The Battle of Brunanburh is an Old English poem.  It is preserved in the "Anglo-Saxon Chronicle", a historical record of events in Anglo-Saxon England which was kept from the late ninth to the mid-twelfth century.  The poem records the Battle of Brunanburh, a battle fought in 937 between an English army and a combined army of Scots, Vikings, and Britons.  The battle resulted in an English victory, celebrated by the poem in style and language like that of traditional Old English battle poetry.  The poem is notable because of those traditional elements and has been praised for its authentic tone, but it is also remarkable for its fiercely nationalistic tone, which documents the development of a unified England ruled by the House of Wessex.

Widsith: Widsith is an Old English poem of 143 lines.  The poem survives only in the Exeter Book, a manuscript of Old English poetry compiled in the late 10th century containing approximately one sixth of all surviving Old English poetry.  Widsith is located between the poems "Vainglory" and "The Fortunes of Men".  Since the donation of the Exeter Book in 1076, it has been housed in Exeter Cathedral in southwest England.  The poem is for the most part a survey of the people, kings, and heroes of Europe in the Heroic Age of Northern Europe: see Tribes of Widsith.

Grendel: Grendel is a being originated from the Anglo-Saxon epic poem "Beowulf" (AD 700–1000), which is considered to be the oldest surviving poem in Old English.  He is one of the poem's three antagonists (along with Grendel's mother and the dragon), all aligned in opposition against the protagonist Beowulf.  Grendel is feared by all but Beowulf.  Grendel is described to have descended from the lineage of the Biblical figure Cain, from Genesis 4 of the Bible, and is usually depicted as a monster or a giant, although his status as a monster, giant or some other form of supernatural being is not clearly described in the poem and thus remains the subject of scholarly debate.

Nowell Codex: The Nowell Codex is the second of two manuscripts found in the bound volume Cotton Vitellius A.xv, one of the four major Anglo-Saxon poetic manuscripts.  It is most famous as the manuscript containing the unique copy of the epic poem "Beowulf".  In addition to this, it contains first a fragment of "The Life of Saint Christopher", then the more complete texts "Wonders of the East" and "Letters of Alexander to Aristotle," and, after "Beowulf", a poetic translation of "Judith".  Due to the fame of "Beowulf", the Nowell codex is also sometimes known simply as the Beowulf manuscript.  The manuscript is located within the British Library with the rest of the Cotton collection.

Offa of Angel: Offa is a legendary king of the Angles in the genealogy of the kings of Mercia presented in the "Anglo-Saxon Chronicle".  He is the son of Wermund and the father of Angeltheow.

History of Herefordshire: The History of Herefordshire starts with a shire in the time of Athelstan (895–939), and Herefordshire is mentioned in the "Anglo-Saxon Chronicle" in 1051.  The first Anglo-Saxon settlers, the Magonsætan, were a sub-tribal unit of the Hwicce who occupied the Severn valley.  The Magonsætan were said to be in the intervening lands between the Rivers Wye and Severn.  The undulating hills of marl clay were surrounded by the Welsh mountains to the west; the Malvern Hills to the east; the Clent Hills of the Shropshire borders to the north, and the indeterminate extent of the Forest of Dean to the south.  The shire name first recorded in the "Anglo-Saxon Chronicle" was derived from "Here-ford", Old English for "Army crossing", the location for the city.  The area was covered first by Offa of Mercia, who constructed the dyke as a boundary to keep warring tribes out of the Mercian kingdom: an early indication of the ambivalent relations with the Welsh.  The shire as an administrative unit was developed from Alfred the Great's Burghal Hidage, and the Shire-reeve courts of the Hundred.  King Edgar the Ætheling was a regular visitor, and founded the diocese, previously part of the see of Worcester, in 976.  The establishment of a centre of law and justice was supported by a monastic chapter that flourished during the Tenth century Reformation.  Hereford's geographical location at the hub of the shire allowed Anglo-Saxon ealdormen to manage affairs; and Hereford played a vital role in the Scandinavian wars until Ralph, Earl Hereford was deposed by the regal Earl Harold Godwinson.

Layamon's Brut: Layamon's "Brut (ca. 1190 - 1215), also known as The Chronicle of Britain", is a Middle English poem compiled and recast by the English priest Layamon.  The "Brut" is 16,095 lines long and narrates the history of Britain: it is the first historiography written in English since the "Anglo-Saxon Chronicle".  Named for Britain's mythical founder, Brutus of Troy, the poem is largely based on the Anglo-Norman "Roman de Brut" by Wace, which is in turn a version of Geoffrey of Monmouth's Latin "Historia Regum Britanniae".  Layamon's poem, however, is longer than both and includes an enlarged section on the life and exploits of King Arthur.  It is written in the alliterative verse style commonly used in Middle English poetry by rhyming chroniclers, the two halves of the alliterative lines being often linked by rhyme as well as by alliteration.

Supporting paragraphs: Kings of the Angles Widsith
Answer: Exeter Book