Leveling a spy/assassin

[Isotopesam]

I've always had trouble leveling up my spy and assassins. I thought using them on rebel armies would help but they keep getting killed all the time. Whats the best way to level a spy and assassin?

[ammo24]

best way is to spy or assassinate any low level diplomat or rebel army with a captain. Make sure that it says there is a good chance for your agent to succeed (at least 70%).

[Isotopesam]

Any benefits on spying on your own towns?

[ammo24]

you don't get any upgrades for the agent but it gives you a better chance to detect and kill enemy agents trying to get in your city and thwart enemy assassins from assassinating a general or sabotaging your buildings. Also raises public order a little.