The Kingdoms Britannia campaign is about the only hope of beating a blitzer in a 1 v 1 MP game. Especially if the Turtle plays England.

First let me elaborate on the concept of culture. Culture replaces religion and adds massive amounts of unrest if you capture a region of a different culture than yours. You will have to slowly convert the settlement to your culture through the use of religious buildings (which convert culture instead of religion) and a good governor who has a high management skill (which replaces piety). Plus there are no priest agents. This won't stop blitzing but it will slow it down. Plus almost every region has a stone fort in a strategic location.

As England, you start off with almost half of the territories in the map so you can go pure turtle. I advise abandoning Ireland though. The high Irish culture will turn Ireland into a money pit. Pull the English troops out of Ireland and sell off the buildings in those territories. Pull those troops to the main island. Then just build up.

The blitzer will have to nail the other AI factions first. That will take a bit of time. In that time, the English turtle can just build and build. I will disagree with Marrow about picking Ireland as the turtle. The blitzer will eventually take all of the main island and Ireland will fall to sheer weight of numbers.

Phonicsmonkey: I'm always up for playing more hotseat games but I think the point is to play ATPG 1 on 1. Also, it doesn't seem like he has Kingdoms yet.