One of the key incidents, early in my WIP, is when there is a civil disturbance in Dover. One of the groups involved flees to Gloucester. The lord responsible for Dover is instructed by the King (in Gloucester) to punish his unruly subjects. The lord declines, raises an army, gets his sons (who are responsible for East Anglia, etc.) to raise their armies, and they march on the king in Gloucester. The king manages to get two other earls (Northumbria and Mercia) to raise their armies, and march to Gloucester to support him. My problem with all this is, what was the sequence of horses galloping across the country to carry the news of the incidents, and instructions to march, etc. such that they all met - coincidentally - at the same place?
Wow, that is a lot of galloping around! I'm not a medieval war expert, but the following is what occurred to me. The king would be anxious to get his troops out onto a field of battle, so as not to be pinned in the city and besieged. (Was Gloucester a walled city at the time? I'm going to assume it was.) So he'd have a strong incentive to name a place for battle. ("Stop this at once you naughty vassals, or else meet me at the field of xyz to settle the matter with swords.") The rebel leaders would want the opposite--to catch the king in the city, unless they knew Gloucester was well-supplied enough to last through a siege. (What time of year is this? A medieval city would be at its lowest ebb in the early spring, when winter stores were running low and before spring crops had sprouted. It would be at its strongest in Novemberish, after the crops were in and the summer stock of animals were slaughtered. The supply levels of the Rebels would follow the same calendar.) So depending on how you want to play it, you could have your rebel lords be honorable and allow a field of battle to be chosen, or to have them be more practical- (and bloody-)minded and have them storm Gloucester. They'd concentrate on the gates, perhaps not all of them, if they didn't have the manpower, but they'd certainly try to control traffic on the river (to avoid re-supplying). I don't know if Gloucester had a "water gate" per se, but I think that rebel forces would definitely collect there if one existed. It seems to me that your rebels would be the ones to have the choice of where to have the battle, since they moved first. Mobilizing a military force is no joke--preparations would lag behind the swift messengers for some time. Also, some of the king's reinforcements are coming from Northumbria, which is not close. Also, if I read this correctly, there are already rebel sympathizers who have fled to Gloucester, and are in the city. I must say this sounds bad for the king. ======== The tl;dr answer to your question is that there would be a flurry of galloping messengers at the start of the conflict, but actually getting the military around where it was supposed to go would take so long that communication about a battlefield location wouldn't be a problem. Also, communication of such things might be moot, since the rebels have an incentive to strike the city, and the ability to strike first. Edit: Of course, since I posted this, I started thinking of all the potential reasons why an attacking army might want to draw out the king's forces rather than let them shelter in place, like maybe it's December and the city is still well-stocked while weather conditions in the surrounding area are terrible. Idk. ymmv.
