Complex sentence: Historian KR Subramanian states the Pallavas were originally not a Tamil power, they were a Telugu power; and Telugu Sources know of a Trilochana Pallava as the earliest Telugu king and they are confirmed by later inscriptions.
Split into simpler sentences: Historian KR Subramanian states the Pallavas were originally not a Tamil power, they were a Telugu power; and Telugu Sources know of a Trilochana Pallava. Telugu traditions know a certain Trilochana Pallava as the earliest Telugu King and they are confirmed by later inscriptions.