I'd be curious to hear about other folks' experience with setting up campaigns outside Salisbury. Do you endeavor to provide as much detail for your home county as the Salisbury example in the book?

In particular, I'm curious about maps: do you prepare a map of all the manors in the county and a random chart for player manors? If so, what sources do you use? Or do you just place manors more or less by fiat?

I ran a campaign set in Leicester under a previous edition of KAP (Lambor in the current), and relied on three works for placing manors. I used the Domesday Book (now accessible online (http://www.domesdaybook.co.uk/index.html)) as my principal source, supplemented by John Speed's Tudor Atlas (also accessible online (http://www.lib.cam.ac.uk/deptserv/maps/speed.html)) and a modern reference volume on the history, geography and geology of Leicestershire. I wanted at least as much detail as was available for Salisbury.

I'm running a Jagent campaign (come friday AD 560!).

I have set up my players in an old barony deep in Morgaines Forest, called Durnay, and for that area I used a modern Ordnance Survey map to provide names and geographic detail. For the main part of Jagent, I wrote short text about all major towns, cities, castles and monasteries, but left other details more sketchy, as Jagent would be more of an backdrop to the Durnay story.

I have however created a host of NPCs through the ages, the whole family of the Count(s), the banneret knights and some of their families, the major knights, some castellans and marshalls and so forth, including, traits, roleplaying notes, views on politics and current events, etc.

In my mind, geographic detail is about local color and verisimilitude, while a good set of fully rounded and thought through NPC is the heart of any campaign, wherever it is set.

Well, my players went and helped Sir Kay to (re-)conquer Normandy, starting our campaign's 'Hundred Years War' equivalent conflict. To reward them with lands and new problems, I took the County of Mortain, handwaved its approximate borders, and then just picked modern towns that sounded good enough at reasonable distance from one another in Google Maps, and hey presto, I had a county!

Who cares if one of those towns/villages didn't exist until 1800s? Not my players, at least. All they care about is how much their manors' income is and how far is the enemy border. Oh, and fortifications. They really want to have fortifications. :P

This is all just how I do it so if I sound didactic I apologise. :-[

I've done two or three campaigns over the years. I've never started with vassal knights so I've never had to worry about assigning manors at the start.
My campaigns are very sandboxy. I usually start with an adventure which naturally has locations. The PKs have often been riding errant which divorces them from their backgrounds. They have free choice about where they go. Land is normally something that is recaptured, conquered, or granted by a grateful patron during one of the early adventures.
From that initial conquest PKs get borders. Once they have borders I decide what's over them. Neighbours etc, trade routes they may have access to etc.
I usually use large scale maps from Pendragon 4th edition products. Smaller scale geography is made up out of whole cloth. I've set campaigns in entirely fictional welsh valleys and in made up marcher geography. I've used the outer hebrides as a backdrop where all the islands, mountains and rivers, stone circles, brochs and barrows etc were real but other than Stornaway all the settlements were fictional. Cities, at least the older ones, are where they are in real life. Villages and individual manors are made up.
I usually use descriptive names for settlements, High Crag, Coldbeck etc. With my new game I'm trying to use old Brythonic language terms to give a slightly foreign feel. My last nights play was the Skirmish of Culvellyn Sands.
I don't map any of the finer detail, manors etc onto the game area map until I need them, which is when the players encounter them in-game. As soon as they e.g. meet a knight from Gilsland I jot down a note about his manor which includes a ruined milecastle on the wall and his daughter who's in love with a bandit, in case the PKs decide one evening to take up his offer to come and hunt with him. Those dashed players will go around remembering these things!
Like Skarpskytten said NPCs are important for giving a feel to an area and names which are particular to the local culture can help with that.
In addition it's probably important to look at the timeline and check what years invasions, great battles and significant events affect the area you're considering because it may influence your choice. I'm currently running a game in Rheged in 496 AD and things there will be very different after the battle of Bedegraine in 512 and even funkier after the dolorous stroke in 514.

Hope this is some help,

GR

I pretty much do what Gentleman Ranker does. My campaign is based in Lindsey and I nick likely manor locations from google maps when I need them (although it helps that I was born and raised in what the book calls Bedegraine, so I'm practically a local).

Wikipedia is a useful resource for settlement info once you have some candidate locations plus a lot of places that have survived to the present day will have some kind of website with little nuggets of historical facts gathered by an enthusiastic local.

Regards
Luke

Thanks for all these great responses! Based on your feedback, I was able to put together a nice little dossier for Wuerensis. The Speed Maps were particularly useful. I also got a lot of great stuff from a book called The Lore of the Land: A Guide to England's Legends which breaks down local English legends by (modern) counties and categorizes them into classes like "Ghosts, apparitions & screaming skulls," "Hidden treasure," Legendary beasts," "Saints & miracles," "Underground passages," "Witches & wizards," and so forth. Highly recommended!

anyone ran a campaign based on 4ed culture (saxons, irish, danes...) books?

We're in Hertfordshire. The Angles' invasion made for fun times!