Flags were originally used as rally-points for soldiers in battle. Our game of "Capture the flag" is one of the hand-downs of that philosophy.
To be visible, the flag had to be bright and simple in its pattern.
Frequently, the location of the Flag was also the location of the King or the general in a given fight.
The United States was the first country that complicated their flag away from the rule of simple: easy to recognize. The English Grand Union flag that we see today is a combination of the English "St. George Cross" and the Scottish "St. Andrew Cross".
Even so, they remain highly visible, a rally-point for their troops.
Previous to the adoption of the Tri-Color flag, France had a White flag. They surrendered a lot, I guess.
Matt missed one of the classics in Flag goofs, though; Italy and Ireland had for quite some years the same colors and position of those colors on their flags. Good thing they never had a war.
