The flag of the Kingdom of Bruis
The Kingdom of Bruis had, like many of the other Ptolemaic rebel nations, a circle in the middle of its flag, which represented change, revolution, a new dawn, and the sun. The Kingdom of Bruis had one of the largest armies of the Ptolemaic rebel nations, and its personal goal was to defeat and destroy any Seleucid opposition, which is clearly represented on its flag by the sword and the skull. Others interprent it slightly differently though, saying that the sword has ripped through the bloodshed (it's red) world (or the sun) and the skull is eating it, and that this flag was a foreshadow of the Expansion War which would later be started by the Kingdom of Bruis. That seems unlikely however.