Yes, I guess I should have called them Originals, but that sounds weird. 3 originals and none of them are a sequel.
To clarify that for you:
4-5-6: Original trilogy (aka The Trilogy) [OT]
1-2-3: Prequel trilogy (aka The Prelogy) [PT]
7-8-9: Sequel trilogy (aka The Postlogy) [ST]