Crusader Kings II

[Monk]

Good job in the unification of the Rus! That's probably one of my favorite places to start at the 1066 date. Lots of room for expansion and freedom to do what you want while still presenting lots of challenges.

I'm still undecided whether I should conquer easternmost duchies. I've left them purposefully in the hands of Cumania (tengri) to maybe force the il-khanate to go south. Down there there is an immensely powerful Sultanate of Egypt having 140 000 levies at the moment. Also, I won't have the time to properly upgrade those holdings so Mongols would assault/conquer them rather easily, giving them warscore quickly. What do you think? A good strategy?

it might even buy you a little time if you leave those duchies as a buffer, say, an extra 5 years before their eventual invasion.

Don't forget assassinations! It may be worth it to try to assassinate some of the best mongol generals. Locate the mongol leader and take a look at his court after the invasion, see if you can select individuals and determine who his best generals are. Something to keep in mind is that the mongols great power comes from their battle tactics, which cannot be used if the AI lacks good commanders. A few well placed (and lucky) assassinations might be the key to winning a crucial fight on the flank that could determine the war.

A few things things to note about the Mongol Invasion:

1. Every new khan can call in reinforcements until the year 1300. But once he does, he no longer can do that during his life time. So you never want to assassinate the khan directly.

2. Every 10-20 years the mongols will return with much less troops and attempt reinvasions, should their initial invasion fail. These will go on until 1300, the mongols will bring anywhere from 20000 to 60000 men in these 'lesser' invasions. Not the doomstacks of the first, but something you must contend with.

3. If they at any time convert they automatically lose the ability to call in new troops.

I like to think of the Mongols (and later Timur) as the boss battles of CK2. They are really tough and they require a lot of planning to approach with a hope of victory. My advice would be to save on the eve of the invasion and then continue in a different slot. If at first you don't succeed, try to refight the war from the beginning and see if you can do any better by adjusting your tactics. The Mongols are meant to be big blob shatterers, so don't be dismayed if you gotta give it more than one try to beat them.