Simplify the following text for a Grade 7 native English-speaking person.
Original: Thus the Hoysalas began as subordinates of the Western Chalukyas and gradually established their own empire in Karnataka with such strong Hoysala kings as Vishnuvardhana , Veera Ballala II and later Veera Ballala III .
Simplified: Some famous Hoysala kings were Vishnuvardhana , Veera Ballala II and Veera Ballala III .