Slitherine

So Austria decided to revolt against my benevolent rule while I was about to capture Smolensk. Immediately I turned part of my army around, including Napoleon's own unit of line infantry, and taught the Austrians a lesson. I gave Napoleon himself the honour of capturing Vienna, after which they promptly surrendered.

BUT:

whereas my units surrounding the city were moved immediately outside the Austrian sphere of influence, the city itself was empty, and Napoleon nowhere to be seen (and I have looked everywhere). He doesn't appear among the commanders I can recruit, either. I don't remember what happened to my conquering unit last time I captured Vienna, but surely they are not supposed to vanish?

Crisis averted. I looked everywhere -- except the new units pool. That's where he was. Doesn't make much sense, though. When I eg. take Moscow (which quite unhistorically causes Russia to capitulate, by the way) I then get to instantly transport the conquering unit all the way back to France. But at least it doesn't vanish.