Even as the northern chant traditions were displacing indigenous Italian chant, displaced musicians from the north contributed to a new thriving musical culture in 12th-century Italy. The Albigensian Crusade, supposedly to attack Cathar heretics, brought southern France under northern French control and crushed Occitan culture and language. Most troubadours fled, especially to Spain and Italy. Italy developed its own counterparts to troubadours, called "trovatori", including Sordello of Mantua. Frederick II, the last great Hohenstaufen Holy Roman Emperor and King of Sicily, encouraged music at the Sicilian court, which became a refuge for these displaced troubadours, where they contributed to a melting pot of Christian, Jewish, and Muslim musical styles. Italian secular music was largely the province of these jongleurs, troubadors, and mimes. One important consequence of the troubadour influence during this period, in Italy and across Europe, was the gradual shift from writing strictly in Latin to the local language, as championed by Dante in his treatise "De vulgari eloquentia"; this development extended to the lyrics of popular songs and forms such as the madrigal, meaning "in the mother tongue." Also around this time, Italian flagellants developed the Italian folk hymns known as spiritual laude.