Simplify the following text for a Grade 4 native English-speaking person.
Original: The Sapa Inca ( `` The Great Inca '' ) , also known as Apu ( `` Divinity '' ) , Inka Qhapaq ( `` mighty Inca '' ) , or simply Sapa ( `` The Great One '' ) was the ruler of the Kingdom of Cusco and later , the Emperor of the Inca Empire ( Tawantinsuyu ) .
Simplified: Sapa Inca was the title of the Inca emperor . Sapa Inca means `` The Great Inca '' or `` The Only Inca '' in Quechua , the Inca language .