On the first map of the Attila the Hun campaign, move Attila away from where you get
him. Wait until one of the Tarkans say "Bleda wastes our time. Let us follow Attila." 
Send Attila up to Bleda, set Bleda's Huns to neutral/enemy, and start killing Bleda. 
Once you get the Tarkans, send them up to help Attila. Once Bleda is dead, go back to
the camp and kill any other Tarkan that do not convert. Once you get the resources 
from Bleda's Huns, go over the northwestern bridge as one of the Tarkans suggests. 
Once you get those villagers, GAIA gives you some resources. Return into the Hunnic
camp to have Bleda's Huns give you more resources.