Complex sentence: The Slavs, a migratory people from northeastern Europe, were subjugated by the Eurasian Avars in the 6th century, and together they invaded the Byzantine Empire in the 6th and 7th centuries, settling in what is now Bosnia and Herzegovina and the surrounding lands.
Split into simpler sentences: The Slavs, a migratory people from northeastern Europe, were subjugated by the Eurasian Avars, and together they invaded the Byzantine Empire in the 6th and 7th centuries. They settling in what is now Bosnia and Herzegovina and the surrounding lands.