ca 5 BILLION BBY

The galaxy is formed by the gravitational collapse of a large cloud of dust and gas. Nearly 10,000 light years in diameter, the galaxy includes over one million inhabited worlds and thousands of intelligent species.
Inside the Worlds of Episode I.
 
 
 
ca 2 BILLION BBY
The Oseon System is created when a rogue star disrupts the formation of a planet and creates the Oseon asteroid belt.
Time Tales.