As I plan this campaign I see 2 possible objectives at the start of it:
1) checking the Polish expansion to the east;
2) stopping the Horde.
The first one does not seem very annoying: I plan to capture Lithuania pretty soon in the game (during 5-7 turns) and hold the two-province border (Lith and Kiev) against any incursions from the west (Polish and possibly Hungarian).
But the Horde! My vision of fending it off is to form an eastern river frontier (Muscovy, Ryazan, Chernigov and Kiev all have river borders with anything to the east which is sure to be held by Mongols). The weak point of this plan is Pereyaslavl that is wide open from any direction. But having watched the Horde's behavior in many campaigns I assume that it will invariably move from Khazar westward to Kiev and I will try to get ready the troops for a huge bridge battle. The Mongols' other possible ways of invasion from Volga-Bulgaria will meet the same fate in Muscovy or Ryazan. After defeating the bulk of the nomads I hope them to direct their wrath southward (to Georgia and further on). The likely pitfall on this brilliant way is the Rus unit roster: no decent spears. But hopefully mercs will step in to help. And when I muster enough force I will try to evict the Mongols from Khazar and Volgo-Bulgaria leaving them a foothold in Crimea.
Any objections or advice that can improve my initial plans?
And what about Khazar before 1230? Should I capture it and leave a small garrison (1 halbs and 1 spears) in a fort on a hill to distract the Horde or should I not dawdle away with it?
Spill out anything you have in mind on the subject.