Gold
From Evony Wiki
Gold is a resource used primarily for paying hero salaries, researching technological advancement, and for the exchange of other resources at a marketplace. By raising taxes you can increase the rate at which gold is collected. It is calculated as a percentage tax against total population. Gold can also be used for praying and blessing. Praying can increase population and increase prestige. Blessing only increase food. Many players who have high gold levels can pray every 15 minutes regardless of the cost.