Complex sentence: Mezghanni has gradually established himself as a literary and cultural journalist and since the 1980s he has participated in numerous poetry festivals around the Arab world and Europe, encouraging him to organize various poetry events and found poetry clubs back in Tunis.
Split into simpler sentences: Mezghanni has gradually established himself as a literary and cultural journalist. Since the 1980s, he has participated in numerous poetry festivals around the Arab world and Europe, encouraging him to organize various poetry events and found poetry clubs back in Tunis.