Question: Modthryth is a reconstructed name for a character who figures as the queen of King Offa in which Old English epic poem?

Context paragraphs:
Thingfrith: Thingfrith was the father of King Offa.  He was the son of a certain "Eanwulf" and was descended from King Penda of Mercia's brother, Eowa of Mercia.  A tradition related by the 13th century "Vitae duorum Offarum" names king Offa's mother as Marcellina, who would thus be wife of Thingfrith were the tradition authentic.

Eadburh: Eadburh (Old English: "Ēadburh" ), also spelled Eadburg, (fl.  787–802) was the daughter of King Offa of Mercia and Queen Cynethryth.  She was the wife of King Beorhtric of Wessex, and according to Asser's "Life of Alfred the Great" she accidentally killed her husband by poison.  She fled to Francia, where she is said to have been offered the chance of marrying Charlemagne, but ruined the opportunity.  Instead she was appointed as the abbess of a convent.  Here she is said to have fornicated with an English exile.  As a result, she was eventually expelled from the monastery and ended her days begging in the streets of Pavia.

Unferð: In the Old English epic poem "Beowulf", Unferth or Hunferth is a thegn (a retainer, servant) of the Danish lord Hrothgar.  His name appears four times in the poem (always spelled Hunferð), at lines 499, 530, 1165, and 1488, as well as in line 980 by the appellation "the son of Eclafes".  The name "Unferth" does not appear in any Old English manuscript outside of the Nowell Codex, which contains "Beowulf", and the meaning of the name is disputed.  Several scholarly theories about Unferth have been proposed.  Unferth is also the name of a character in the modern novel "Grendel" by John Gardner, based upon the "Beowulf" epic.

The Faerie Queene: The Faerie Queene is an incomplete English epic poem by Edmund Spenser.  Books I to III were first published in 1590, and then republished in 1596 together with books IV to VI.  "The Faerie Queene" is notable for its form: it is one of the longest poems in the English language and the origin of a verse form that came to be known as Spenserian stanza.  On a literal level, the poem follows several knights in an examination of several virtues, though it is primarily an allegorical work, and can be read on several levels of allegory, including as praise (or, later, criticism) of Queen Elizabeth I.  In Spenser's "Letter of the Authors" he states that the entire epic poem is "cloudily enwrapped in Allegorical devises," and that the aim of publishing "The Faerie Queene" was to "fashion a gentleman or noble person in vertuous and gentle discipline".

Myrging: The Myrgings were a clan and people of Saxon origin who, together with their king Eadgils, are only mentioned in the Old English poem "Widsith".  They are mentioned as the people of the scop Widsith.  They appear to have been the neighbours of the Angles and Offa of Angel, who was involved in a war against them.  Perhaps they were a dynasty or clan competing for power with Offa over the rule of the Angles, though Offa slew two Myrging princes, probably the sons of Eadgils (not to be confused with the Swedish king Eadgils); this Eadgils was later killed by Ket and Wig, the sons of Freawine, a governor of Schleswig who challenged Eadgils to combat while he was pillaging in the Angle lands.  Freawine was killed in combat and the Myrgings may then have overrun Schleswig, as they are said to have settled or had holdings at Schleswig, though they were eventually defeated by Offa, who extended the boundary with them to Fifeldor.

Yngvi: Old Norse Yngvi, Old High German Inguin and Old English Ingwine are names that relate to a theonym which appears to have been the older name for the god Freyr.  Proto-Germanic *Ingwaz was the legendary ancestor of the Ingaevones, or more accurately Ingvaeones, and is also the reconstructed name of the Elder Futhark rune ᛜ and Futhorc rune ᛝ, representing "ŋ".

Grendel's Den: Grendel's Den is a bar and restaurant in Harvard Square in Cambridge, Massachusetts, located at 89 Winthrop Street.  The establishment is frequented by both students and professors of Harvard University as well as many others from the Cambridge and Boston area.  The name was a reference to Grendel, the antagonist in the Old English epic poem of Beowulf.

Beowulf (2007 film): Beowulf is a 2007 British-American 3D motion capture epic fantasy film directed by Robert Zemeckis and written by Neil Gaiman and Roger Avary, based on the Old English epic poem of the same name.  The film was created through a motion capture process similar to the technique Zemeckis used in "The Polar Express".  The cast includes Ray Winstone, Anthony Hopkins, Robin Wright Penn, Brendan Gleeson, John Malkovich, Crispin Glover, Alison Lohman, and Angelina Jolie.  It was released in the United Kingdom and United States on November 16, 2007, by Paramount Pictures and Warner Bros.  Pictures, and was available to view in IMAX 3D, RealD, Dolby 3D and standard 2D format.  The film received positive reviews from critics and it earned $196.4 million on a $150 million budget.

Modthryth: Modthryth, Thryth ('strength', cf. Old Norse Þrúðr, the daughter of Thor), and Fremu are reconstructed names for a character who figures as the queen of King Offa in "Beowulf".

Beowulf: Beowulf ( ] ) is an Old English epic poem consisting of 3,182 alliterative lines.  It may be the oldest surviving long poem in Old English and is commonly cited as one of the most important works of Old English literature.  A date of composition is a matter of contention among scholars; the only certain dating pertains to the manuscript, which was produced between 975 and 1025.  The author was an anonymous Anglo-Saxon poet, most likely from the Kingdom of Northumbria, referred to by scholars as the ""Beowulf" poet".

Supporting paragraphs: Modthryth Beowulf
Answer: Beowulf