I'm playing as America, and this is in around the classical/medieval era, and Aztec declared war against me for no reason at all. I had the worst army in the game but took over 4/5 of his cities before he surrendered.
Then there were notifications telling me that there are enemies spotted around one of my cities, and it turned out to be 2 barbarian longswords men, and then there were 2 more spearmen that spawned at the same place, then there were 2 horsemen spawned in the city to the north of Aztec's capital.
Is this a glitch? I have 23 unhappiness, and it fluctuates between that and 21 very often, and my income fluctuates between -2 to 8.
Never had this happen before. And it seems that Barbarians spawn in pairs, and they don't spawn more until the pair is killed
Best Answer
Barbarians might spawn in your territory when your population is very unhappy. You can tell if your population is very unhappy by an angry looking happiness icon. THere are several other consequences from your population being unhappy:
Source: Civilization V wiki happiness section