The clash within the Valsedian asteroid belt represents one of the conflicts during the Galactic Civil War.
Somewhere in the timeframe spanning 2 BBY to 4 ABY, the forces of the Galactic Empire obliterated a Rebel installation situated within the confines of the Valsedian asteroid belt. Admiral Gaen Drommel spearheaded this Imperial endeavor.
As a consequence of his triumph, Admiral Drommel was later granted authority over the Executor-class Star Dreadnought known as the Guardian.