Comment by inglor_cz

There is a difference between devotional art inspired by religion / mythical events long past (Aeneid etc.), and between the sort of propaganda that the modern totalitarian state demands, which usually centers around some living or freshly dead leader.

I'd be open to discussion where the exact limit is. Lenin died in the 1920s, Marx even earlier, but those two were frequently depicted in Communist propaganda of the 1980s.

So it is probably "hundreds of years".