Lol, do you know how ridiculously boring that would be? In the real world, there were diplomatic missions every few years. In the meantime, you just sit at your throne and do fuck all except take money from your serfs. I don't think it's a very good idea due to the enormous delay time for finding out what's happening abroad, and not to mention the very high financial cost of finding out almost any information about what's happening away from your lands (or indeed, in your own lands if you control a large area).
You know how Populous[1] did the whole "God Game" thing by representing the world you're working on as being on a table, with a book in the background giving you the bigger atlas, etc...
...Then how about an interface which is much like a Patrician's desk, with all the papers and such needed for managing one's domain being there on the desk, and when your attention is drawn to a so-far unrepresented area (or periodically, as the clerks who work for you bring in updated information, everything from bits of news to updated geopolitical maps) a new bit of parchment is put into the pile with the relevant information.
There'd be time-delays in
gathering this information, although one thing you might do at your desk is to write edicts to set up a better courier route to a given city, or development of everything from pigeon-post to whatever your top tech-level of communications might be. There'd also be the possibility of errors (or downright misinformation) creeping into this situation is another hurdle to cross.
In fact, you'd be best advised to orchestrate the creation of a covert backchannel or two to augment the official diplomatic communications... Not that you'd
necessarily be able to fully trust these, either, of course... And orders to the field may also be intercepted and/or changed by your enemies, or misinterpreted/ignored by the actual intended recipients (or 'trusted' intermediaries) in either wilful disobedience or through sheer incompetence. The tendencies towards which you might well be able to have detected if you ask the right questions or compare the right documents, or even just take notice of the right reports.
So, after all that, there's nothing like trying to put down a rebellion in a distant city with a force of arms that is
actually nowhere near the city, or still responding to previous orders, or has been the main reason
behind the rebellion in some way or other.
In other words, it'd all be part of the game... Not that you couldn't (in a suitably time-compressed manner) go on a "Royal Progress", or similar expedition based upon your exact relationship with the territory you control (changing the relative temporal and information separations between oneself and various parts of your empire, in the process), and I could even imagine discarding/covering the glittery (or at least well-groomed) garb of your daily 'rulership', donning a nondescript cloak and sneaking out to mingle with the masses outside of your current citadel, so as to get a bit of 'word on the street' first hand... With or without a discreet (or otherwise) bodyguard or any way of convincingly throwing off the cowl to reveal your full grandeur and (hopefully!) preventing some wrong being committed against yourself or another... In the latter case, to reward a loyal subject or noble-acting street-urchin and/or invite them to join your retinue or family, or to be impressed/cowed enough to convince them to become an agent for your wishes (keep their ears to the grounds, set their eyes to the horizon, use their voice to convey your own message more strongly, set their hands towards 'your good/evil works', whatever...).
Oh, the possibilities...
Oh, the coding!!!
(I could see it being a bit populous, a bit war-strategy, but some parts like Thief or of a similar ilk... And it could be based around just about any genre from Iron Age to Space Age...)
[1] Well, maybe you don't, if you're a young'un. But take my word for it. Or I'm sure you can find some sort of screenshots of it without too much searching. Please don't let me allow the bit of your brain containing your Google-Fu skills become vestigial and withered through inactivity.