over 2 years ago - AndrewT - Direct link
And here we are.

If you have a huge empire covering, say, 1/4 of the board or more, this is a known issue - you can probably find Bug Report entries about it. Most likely there are just too many units for the game to handle well.  
over 2 years ago - AndrewT - Direct link
GGraulus said: Maybe off topic: but same issue here: extremely slow game all of a sudden (nothing changed to my PC, and I'm just playing as the duchy of Brabant, not a big realm...).

No similar claims under bug reports, so I'm replying here.
Please start your own thread, with full system details and problem history. Thanks.