From Wookieepedia, the Star Wars wiki.
The Battle of Parein II 4 was a battle during the Clone Wars.
The battle saw the debut of General Grievous's wheel bike. Leading his forces into battle, the droid general smashed the Republic opposition.
At one point during the conflict, Jedi General Sannen tried to confront Grievous, but was almost immediately killed when an IG-100 MagnaGuard thrust an electrostaff through his throat.
Valin Draco fought as a military commander in this battle, but was injured and left for dead. He was later hunted by a nighthunter and after a vicious fight, managed to subdue the beast and befriend it.
Draco would be believed missing until after the Clone Wars ended, where he emerged as an Inquisitor for the new Galactic Empire.