Complex sentence: In the seventh century, an addition to the Jewish population was made by Jewish immigrants fleeing from the persecutions of the Visigothic king Sisebut and his successors escaped to the Maghreb and settled in the Byzantine Empire.
Split into simpler sentences: In the seventh century, Jewish immigrants came to North Africa after fleeing from the persecutions of the Visigothic king Sisebut and his successors. They escaped to the Maghreb and settled in the Byzantine Empire.