Complex sentence: The poet Cielo d'Alcamo (known also as "Ciullo d'Alcamo"), author of the contrasto "Rosa fresca aulentissima" and who wrote in vernacular in the 12th century, was from Alcamo.
Split into simpler sentences: The poet Cielo d'Alcamo (known also as "Ciullo d'Alcamo") was the author of the contrasto "Rosa fresca aulentissima". He wrote in vernacular in the 12th century and was from Alcamo.