The Occitan language goes by many names for its various dialects and was the ordinary language spoken in the South of France until well into the 20th century. Its nearest relative is the better-known Catalan. But in Dante's day, a standardized variety of Occitan was the language of lyric poetry, and many who were not French, geographically speaking, wrote verse in it.
When Dante puts the troubador (or trobador in Occitan) Arnaut Daniel, inventor of the bizarre poetic form the sestina into Purgatory, he has him speak in his native tongue, the last words spoken by any soul in Purgatory:
Versi d'amore e prose di romanzi
soverchiò tutti: e lascia dir li stolti
che quel di Lemosí credon ch'avanzi. (...) "
Io mi fei al mostrato innanzi un poco,
e dissi ch'al suo nome il mio disire
apparecchiava grazïoso loco.
E cominciò liberamente a dire:
"Tant m'abellis vostre cortes deman,
qu'ieu no me puesc ni voill a vos cobrire.
Ieu sui Arnaut, que plor e vau cantan;
consiros vei la passada folor,
e vei jausen lo joi qu'esper, denan.
Ara vos prec, per aquella valor
que vos guida al som de l'escalina,
sovenha vos a temps de ma dolor!"
Poi s'ascose nel foco che li affina.
The Dorothy Sayers translation renders these lines as follows, using Border Scots as a rough analogue:
Then I: "Your verse, forged sweetly link by link,
Which while our modern use shall last in song,
Must render precious even the very ink." (...)
I to that soul he'd shown advanced a pace,
Begging he would vouchsafe his name to me,
Who hoped to write it in an honoured place;
And he at once made answer frank and free:
"Sae weel me likes your couthie kind entreatin',
I canna nor I winna hide fra' ye;
I'm Arnaut, wha gae singin' aye and greetin';
Waefu' I mind my fulish deeds lang syne,
Lauchin' luik forrit tae the bricht morn's meetin'.
Pray ye the noo, by yonder micht that fine
Sall guide ye till the top step o' the stair,
Tak' timely thocht for a' my mickle pine" —
Then veiled him in the fires that fine them there.--