R2-D2 had a very stressful few scenes early in Revenge of the Sith, first because Anakin and Obi-Wan were attacked by buzz droids as they attempted to approach General Grievous' ship and then ...
the droid army has become an important part of the galaxy's history, although their fate is never truly shown at the end of the Clone Wars in Star Wars: Episode III - Revenge of the Sith.