Complex sentence: In the 670s, the Bulgars were pushed south of the Danube by the arrival of the Khazars, and in 680, Byzantine forces sent to disperse these new settlements were defeated.
Split into simpler sentences: In the 670s, the Bulgars were pushed south of the Danube by the arrival of the Khazars. In 680, Byzantine forces sent to disperse these new settlements were defeated.