Flags are one of those items we tend to take for granted nowadays, but if you trace their history back throughout the centuries you quickly get a healthy appreciation for these seemingly innocent pieces of fabric.

If you search back into history far enough it is believed that flags were in use within the complex cultures of the Ancient Indians and Chinese.  It is thought that from these cultures the awareness and use of flags spread, making their way into Persia at which point they were adopted by the Achaemenian and Sassanid dynasties.  Rome too was interested in flags, initially using a stiff standard for identifying it's many legions before moving on to partially flexible and wholly flexible flags.  It is important to note that these early incarnations of flags were probably not the way we think of flags today - they may have been stiff, stretched over frames, or even made out of leather or wood.

By the Medieval period flags had spread - probably with the help of the Roman Empire - to nations all over Europe, Asia and Africa.  Flags began to be used for battle-field identification, a job that flags still have to this day.  The great sea explorers that ventured out towards the New World in the centuries that followed also relied on flags for communication - not for close-up battles but in order to determine friendly ships from foes.  This is the era in which the popularized pirate flag (skull and cross-bones) is believed to have emerged.  It was also the age in which the standard military communication flags were developed and adopted en-masse.