1999 A.D.

Lavos Timeline

-The Arris Dome is controlled by the Guardia family line. 
-Lavos awakens. 
-Truce is attacked first, then Porre, Choras, and Medina.

Keystone T-1

-Lavos appears and is defeated by Crono's party.
-The timeline that occurs after the Apocalypse is sent to the Tesseract.

Keystone T-2

-Lavos is probably destroyed by the heroes of time.

From: Chronology