It wasn't, but many works have lost any indication of authorship due to the fragmented quality of what has been left to us.
Medieval literature was copied by hand and many volumes were lost over the following centuries. Names of authors did not mean much to the medieval citizen, only if they were very famous, which would add to the credibility of what was contained in the text. Thus, unimportant names would sometimes be left out of a book during the process of copying, if they were present at all (books which contained collections of sermons or short stories from different authors would seldom credit the authors). If the original volume was subsequently lost, any written proof of authorship was lost with it. On the other hand lots of texts were attributed to authors who actually had nothing to do with their conception. This was done by authors who wanted their texts to be widely read but weren't famous enough to accomplish this by publishing it under their own name.
Some books were deliberately devoid of any names because these volumes contained controversial or anti-establishment utterances, and any author connected with these books would be arrested for heresy or disturbance of public order and often condemned to death.
Robert William Ackerman has written: 'Backgrounds to Medieval English literature' -- subject(s): History, Literature, Medieval, Medieval Literature
The writer of Beowulf is unknown. The epic poem was likely composed by an anonymous Anglo-Saxon poet in the early medieval period.
Michael Earl Ralston has written: 'A typology of guides in medieval literature' -- subject(s): History and criticism, Literature, Medieval, Medieval Literature
Mario Martins has written: 'Estudos de literatura medieval' -- subject(s): History and criticism, Literature, Medieval, Medieval Literature, Portuguese literature
Jane Chance has written: 'Assembly of Gods' 'Medieval mythography' -- subject(s): Civilization, Medieval, Classical influences, Criticism, Medieval, Ecole de Chartres, Historiography, History, History and criticism, Latin literature, Medieval and modern, Literature, Medieval, Medieval Civilization, Medieval Criticism, Medieval Literature, Medieval and modern Latin literature, Mythology, Mythology, Classical, in literature, Roman influences, Theory 'Tolkien the Medievalist' -- subject(s): History, Nonfiction, OverDrive 'Woman as Hero in Old English Literature' -- subject(s): History, English literature, History and criticism, Sex role in literature, Heroes in literature, Women, Women and literature, Heroines in literature, Women in literature 'Christine de Pizan's Letter of Othea to Hector' 'The Genius figure in antiquity and the Middle Ages' -- subject(s): Ancient Civilization, Ancient Literature, Civilization, Ancient, Genius (Companion spirit), History and criticism, Literature, Ancient, Literature, Medieval, Medieval Literature 'Tolkien's art' -- subject(s): Criticism and interpretation, England, English Epic literature, English Fantasy literature, Epic literature, English, Fairy tales in literature, Fantasy literature, English, History, History and criticism, In literature, Knowledge, Medievalism, Middle Earth (Imaginary place), Mythology in literature, Mythology, Germanic, in literature
An anonymous German medieval artist.
Joan M. Ferrante has written: 'Woman as image in medieval literature from the twelfth century to Dante' -- subject(s): History and criticism, Literature, Medieval, Medieval Literature, Women in literature 'Dante's Beatrice' -- subject(s): Religion, Beatrice Portinari, In literature, Characters, Religion in poetry 'In pursuit of perfection' -- subject(s): Courtly love, Courtly love in literature, History and criticism, Literature, Medieval, Medieval Literature 'Woman As Image in Medieval Literature' 'The political vision of the Divine comedy' -- subject(s): Political and social views, Politics and literature, Dante Alighieri,, History
Alexandru N. Cizek has written: 'Imitatio et tractatio' -- subject(s): Ancient Rhetoric, Classical literature, History and criticism, Imitation in literature, Literature, Medieval, Medieval Literature, Medieval Rhetoric, Rhetoric, Ancient, Rhetoric, Medieval, Theory
Medieval literature is any literature after the fall of Rome in the west in 476 AD (CE) and around 1450 when Gutenberg invented the printing press.
anonymous just means they didn't know who did it. Also "traditional".
Wendy Pfeffer has written: 'The change of Philomel' -- subject(s): History and criticism, Literature, Medieval, Medieval Literature, Nightingale in literature
Bernhard Pabst has written: 'Rundfunk- und Fernsehbauteile' -- subject(s): Equipment and supplies, Radio, Television 'Prosimetrum' -- subject(s): Classical influences, Classical languages, Classical literature, History, History and criticism, Influence (Literary, artistic, etc.), Latin language, Medieval and modern, Latin prose literature, Medieval and modern, Literary form, Literature, Medieval, Medieval Literature, Medieval and modern Latin language, Medieval and modern Latin prose literature, Metrics and rhythmics, Theory