How far apart can two cities/towns/etc be, given that order must be (effectively) maintained?

Question

Given a monarchy, how far apart can two cities/towns/etc be situated, while still maintaining order and power? Alternatively, think about it this way: given any random settlement area, what is the farthest another settlement could be that the second is still controlled by the first?

What factors outside of technology could change this? Think socially, politically, and so on.

Assume medieval technology, give or take a century.

I've looked at the answers already posted, and they mostly seem to deal with empires and the largest expanse they conquered.
Note that I'm not asking for what the largest expanse of an empire can be, but rather more specifically farthest reach of power between cities or towns.

Answer 1

EDIT: Ok, in answer to the edited question, I'm completely redoing the answer. I did leave my old answer below if anyone wants to read it.

The distance two towns can be apart and still be under one regime is infinite. But the distance between two towns that a single governor/monarch can handle (i.e. no act in, besides maybe a simple mayor to handle civil disputes), would be about a week ride. Because the monarch would have to go there to see exactly how things are doing. A Garrison of solider would be under his command, not the "mayors" so he would need to be able to give them commands.

Social problems could reduce the distance. If there was a high chance of an uprising, the monarch would need to be closer to be able to keep a better eye on things.

---

Old Answer

That would definitely depend on what technology the civilization had. With even current day human technology, world-wide domination could be considered possible (the English did it with even less sophisticated technology). Instant communication, and even better, instant travel would be huge in deciding how much distance apart two areas could be and still be ruled by one person.

As suggested, good, local authorities would also be needed for any sort of distance. A ruler can not be in any place all the time, even with the above technologies. But a good local ruler can keep an eye on things and make basic decisions without his leader.

The leader would also need to keep in touch with the people. If you don't know what your people want/need you won't be able to keep them happy/rule them. Or the leader could be a dictator, but either way the leader would need to know where problems were. This is complicated by larger distances, so that can put a limiting factor.

So it is hard to give a number on how far away two areas can be to be ruled by the same person, a specific set of technology/circumstances would need to be given for that.

Answer 2

Roman empire was huge. And it lasted a lot of centuries on the basis of being divided on provinces and the fidelity of the Governors (and the roads for haveing an effective menace of sending legions).

Spanish empire was huge and sparse. Again, Viceroys and Governors were key to its (time limited) success.

Russian empire was huge and lasted for centuries. It started with medieval weapons, so it is not a matter of modern weapons nor communications. Again, fidelity. Remember Miguel Strogoff.

Alexander's Empire was huge and it did not succeed. His generals were not loyal to his blood but created kingdoms on theirselves.

The pattern repeats over and over: delegation of power, as much as necessary, on strong but loyal governors.

EDITED New answer below for the sake of the rephrased question

This depends on several things. Roman empire was a single settlement (Rome itself) and it still controlled the "known world". But if you are thinking on direct control, with a single governing body (a mayor or king, a counsel like in Sparta, or any other) directly controlling both towns from one, the most important point is loyalty. Settlers from town A creating a settlement B near a silver mine would still have their families and issues in A, so they will be loyal to A (if they already were). With time, and with the development of B, it becomes more and more self-sustained, and eventually an independent town. How long this takes and how friendly is the new town depends on the feelings of B citizens and on the attitude of A towards B. Openness and friendliness causes B to become an independent friendly city with "a common history" and multiple business between them, on the long time. Metropoli/colony thinking causes B to end revolving, causing either an angry independence (USA from England) or a permanent colony status that must be maintained by force. In this last case, you need to go there quite quickly, so maybe you can not keep control of B from more than some travel days ago.

Answer 3

I would approach this from different angle. How loyal and competent is the governor of the distant city? I see this as the most important question.

Of course, technology plays some role. If the fastest messenger can get there in a day it's easier than if he can get there in a week, or even in a month. But for if you don't rely for them to provide you military help when some unexpected enemy attacks you on the other end of your empire, all you need is that the governors of the colonies send you taxes and when you send there messengers asking for soldiers or some other special help, the order will be obeyed. This is a matter of organization, not much of communication technology.

Look at Spain and its colonies in South America as an example. Ships were slightly faster, but otherwise communication in 16th and 17th century was not faster than in Middle Ages. Still, Spanish governor in Lima or any other distant city was able to maintain order in his province. And the order lasted until 19th century, when the inhabitants of most colonies decided they need independence.

Whether it could be even better if the king visited the colonies sometimes is a question; I guess that the time spend on a ship, far of the court where all the diplomats and messengers could easily find him, would hurt the empire much more than slightly less control over the colonies.

So space is not a question if the king is sensible and local stewards compenent and loyal.

Answer 4

Theoretically? infinite,

In reality it depends on a. the technological level of the society, b. the power of those in charge (their military, bases etc) and c. how accepted the power of those in charge is.

If, for instance, you have a medieval society with the the man in charge being disliked or unaccepted by the people (say he invaded and took over the land) then to keep order he may need to have armed strongholds roughly 30 miles apart to keep order over the people. This is because 30 miles is about a days march, so if there is an uprising those 'keeping the peace' do not need to travel far to counteract it and should a stronghold go under siege then the nearest strongholds can quickly send aid.

Of course, as strongholds/castles are expensive you may only have a high density of them in strategic locations or where uprisings have occurred previously.

This answer was based off of England after 1066 when William the Conquer came to power. This was his method of keeping power (along with destroying everything with fire should an uprising occur)