What happend betweeen EP III AND EP IV?

There's a big gap and was wondring what happend between EP 3 and 4.
Alot of things must of happend when the twins (luke Liea) where growing up.

Dont tell me about the clone wars plzz

The Force unleashed and other stuff.

Half the Rebel campaign from Galactic Battlegrounds. 1/4 of the campaign from Battlefront II. The Force Unleashed. The Han Solo Adventures and Han Solo Trilogy. Land Calrissian trilogy.

Go on Wookieepedia and look up the individual years between Episode III and Episode IV. That would be the year 19BBY and the year 0.