My second city, Memphis, was only defended with a single un-promoted Warrior when I lost it to the Barbs

blush: major mistake #1

). Plus I settled it on a riverside plains tile; I think the better option would have been 1W on a grasslands hill for a little more defense. The other two cities I lost to the Barbs were to Spearmen defeating my War Chariots. I had no Copper, and the Barb Spearmen showed up well before I had researched Iron Working (

should have made that a higher priority without Copper nearby

). Chopping out The Great Wall as others have done would have made a big difference in my game.