Commentary Purg XXIV 56

In a single line Bonagiunta crosses off the list of illustrious precursors two of the great poetic figures that preceded Dante, Giacomo da Lentini (died ca. 1250) and Guittone d'Arezzo (ca. 1230-94).  Giacomo was the first major Italian practitioner of lyric, and is looked upon as the inventor of the sonnet and as the founder of the so-called Sicilian School, the first group of writers of lyric in Italian, taking their models from the writers of lyric in Provençal.  Dante is later still harder on Guittone (see [Purg XXVI 124-126] and C.Purg.XXVI.124-126) who, as Dante came to poetry in the 1280s, was perhaps the pre-eminent Tuscan poet.