In March last year my friend Nick and I went to Rochester (UK) and came under the spell of the castle and its siege in 1215. King John took the castle after a furious siege which included mining the outer wall and a tower of the keep. And even that didn't settle the contest. The defenders retreated into a defensible corner of the castle and only surrendered a week later when food ran out.
This led us to the rather unknown First Barons' War where John defended his rule against a rebellion by 2/3rds of his vassals, combined with Scotland and France. And all this happened after John had signed the Magna Carta (which surprised me), although he did so half-heartedly.
Also, it turned out that John had his enemies largely beat by the time of his sudden death late in 1216. This included the French Dauphin who had invaded Britain at the behest of the rebels.
On the way back I picked up Ralph Turner's King John, England's evil king? as well as Carpenter's The Struggle for Mastery 1066-1284 at Gatwick. This is proved fascinating reading. So far I'm learning about John's early life and administration of England and the French possesions (basically Western France from Normandy to the Pyrenees).
The Cambridge Illustrated Atlas of Warfare: the Middle Ages also has a few pages with great maps showing the conflict and Hillaire Belloc's Warfare in England provides some brilliant insights in the geographical importance of royal castles such as Windsor and Dover.
All this makes for a great game, as the whole thing is finely ballanced between John's control of strategic castles and highly trained and mobile army against a host of enemies which are in the end mostly a result of him being an utter prick. His death may even have saved England from French domination as John's young son Henry (III) was a much more agreeable monarch than French Dauphin Louis.
John has a rather bad reputation, which doesn't entirely do him justice. He was an utter prick, but so were his father Henry II and brother Richard Lionheart. Richard's saving grace was his generosity, but his generous spending on his crusade, then his bail from captivity, followed by continuous war against France to retain hold of Normandy plundered the treasury.
On the opposing side the kings of France in this era were able to extend their hold over France and increase their income, slowly swinging the balance of war in their favour.
So John inherited a mostly bankrupt country from which he tried to squeeze the last drops.
The treasury was mostly filled from the English possessions as the power of the kings was greater here than in their other lands of Anjou, Normandy and Acquitaine. This was always unlikely to ingratiate him with the barons.
This is a situation reminescent of the Spanish Habsburgs who drained Castile in the 16th and 17th centuries to fight their wars abroad because it was the only part of their empire they could control. In that sense the Angevin Empire was as weak as other patchwork realms where local elites jealously guarded their ancient rights, and may not have stood much chance of surviving longer than the half century it did.
John's character didn't help, but he was a sound administrator and a capable commander, as his early campaigns in Normandy show, but even more so in 1215-1216, where he combined a small but high quality field army with a carefully laid out system of royal castles that allowed him to race from Rochester to Edinburgh in just over a month and then back south again in as much time. He also used his strategic mobility to outmaneouvre the rebels and troops of Louis in 1216.
Another tip is Lewes, which also has a nice castle and sets the scene for the first battle in that other Barons' War (1264).
This post was published earlier (in a slightly different form on Fortress Ameritrash