The imperial guard are the fellows with plumes on their helmets standing against the walls holding torches(and the two flanking the Emperor's dais). They did nothing during the fight, nor did they run afterwards.
That's right.. However, when the Princess went to the Emperor's bedchambers none were present. They had ran due to the quake. That's what my comment is referring to. Not when they were rounded up and summoned back to the throne room by the Princess' guards on their return to the palace.