at approximately 19.30 napoleon committed his last reserves in a final effort to obtain victory. as prussians arrived to bolster wellington’s flank, veterans of the french imperial guard advanced to 'finish the job'. the british infantry, exhausted from the continuous cannonade they had received all day, rose to meet them. the musketry of the british guards brigade defeated napoleon’s finest troops. they fled, and the whole french army joined them in retreat. wellington ordered his entire line to advance and the french were driven from the field.