I'd use photoshop cs2 for this map. Started with a simply conture of the landscape, put a pattern (or better, in this case, tons of patterns) on it and added some mountains / trees with a selfmade brush. At least followed the names of the lands and citys, some decoration elements and it was finished.
As I started mapmaking with photoshop (it was around 2004), I created the file, I'm still working on today. So it is impossible to tell, how long this map took me to create. Too long, I expect.
greetings and a happy new year,