Just like the title says, I'm curious as to how your longest mission took.
For example I remember that my longest mission was the one where you had to get a lot of monument rating, the one where you build the Sphinx and two pyramids, that one took about 53 in-game years if I recall correctly.
Imagine all the generations that would have went by in my egyptian family.

So how much did your longest mission last?

The longest mission by far is Hetepsenusret, but I can't remember how long I last took on that one, despite having played it within the last year... It probably took 60-70 in-game years.