Complex sentence: They were the largest and best attested chiefdom of the Timucua subgroup known as the Mocama, who spoke the Mocama dialect of Timucuan and lived in the coastal areas present-day northern Florida and southeastern Georgia.
Split into simpler sentences: They were the largest and best attested chiefdom of the Timucua subgroup known as the Mocama. They spoke the Mocama dialect of Timucuan and lived in the coastal areas present-day northern Florida and southeastern Georgia.