Complex sentence: Pausanias VII, 1.7 The Ionians went to Attica and mingled with the population there, before many people finally emigrated to the coast of Asia Minor, founding the historical region of Ionia.
Split into simpler sentences: Pausanias VII, 1.7 The Ionians moved to Attica and mingled with the local population. Later many people emigrated to the coast of Asia Minor founding the historical region of Ionia.