On the German board someone posted, that his ships disappeared just after WINNING a battle against pirates. I, too noticed some cases where armies seem to disappear randomly. E.g. in a recent game the following situation arised:
France and Cologne, not allied, were both at war with Spain. They besieged Artois together and Cologne had a 60k army in that siege. The city fell and came under French control (because of the better leader). Then France at once settled for indemnities. The city went back to Spain and the army of Cologne (all the forces they had!) was simply gone. Although Cologne maybe could have disbanded the army, I don´t think that´s very likely.
Hartmann
France and Cologne, not allied, were both at war with Spain. They besieged Artois together and Cologne had a 60k army in that siege. The city fell and came under French control (because of the better leader). Then France at once settled for indemnities. The city went back to Spain and the army of Cologne (all the forces they had!) was simply gone. Although Cologne maybe could have disbanded the army, I don´t think that´s very likely.
Hartmann