I was watching Gladiator today and noticed that they had hundreds of flags on top of the Colosseum in the movie. That got me thinking, did ancient civilizations such as Rome, Carthage, Greece, and others use flags? If they did use flags, what did they use them for decoration? War? Or did they have other uses for the flags? And what did some ancient flags look like?
Apologies if this has already been asked, I looked and could not find a similar question.
Sorry that I'm not answering to your specific question, however I can answer that Ancient China did use flags. They were often flown on castles to show which warlord controlled cities as well as flown during battle. They were generally one or two colors and also bared the family name on the flag (Yuan, Zhang, Liu etc).
The colors chosen were based on the Chinese principle of ["Wu Xing"] (http://en.wikipedia.org/wiki/Wu_Xing). That is, associating certain colors with the elements of nature. Dynasties that succeeded each other often chose the opposite element and therefor imperial color. Qin for instance, was Black (Water) while the Han chose Red (Fire). (Edit)- Would like to add that the Han's colors were not always red, and were originally black (water) and later changed to red. This also changed during the Eastern Han, when the color was changed to yellow.
There were certainly battle standards that were similar to flags, like the battle standards of the Roman legions and the standards of the Sarmatians . The Greeks had a variety of symbols that represented the various kingdoms or cities, the most commonly known ones would be the Lambda for Sparta, Vergina sun for Makedon and the owl for Athens. These symbols served a similar function as a flag, allowing the person to identify the origin of the whatever held the image. The idea of national flags that we have today arose with the ideas of nationalism in the 18th century.