AI doesn't pay mercenary upkeep?

[Dragatus]

I suppose that might contribute to why Constantinople is known as the tech capital of the world.

 

[Naughtius Maximus]

Damn that's clever. I've never thought of that or seen someone do that before. Handy little truck for vassal holy orders and the like.

I usually burn all my tech points on 3-4 select techs, having another ruler spending their tech in my capital indiscriminately the way the AI does on the lower techs could be useful as hell.

I guess the ecumenical patriarch also does this until he takes extra land from the start for the byzzies.

It's better if you give it to the Holy Sepulche when they arrive. The Guard ususally converts to Orthodox regardless of whether or not you're Iconoclast, and are always Norse. That negative opinion combo makes them more likely to rebel, unfortunately. They arrive so much earlier in the game though that I personally felt it was worth it.

But yeah, Constantinople has 1 Emperor, one King (Patriarch,) and one potential Duke (Guard/Holy Order) contributing to tech, on top of the tech lead it starts with. Population 99% Spies.