OK, I have put quite a lot of thought in this, I believe it would be a really nice addition to the game:
Georgians. They had a pretty long-lasting medieval kingdom in that part of the world, have their own script, language and had a separate branch of orthodox Christianity.
Should share Eastern European architectural style but with having access to Steppe Lancer and Camel Rider lines
Georgians
Infantry and Cavalry civilization
Bonuses (Bonii?):
Units have no penalty when fighting uphill or below a cliff, nor receive bonus damage from their enemies on higher elevation. If this is too OP, then reduced penalty and reduced bonus damage from their enemies.
Trees give 25% (33% or even 50%?) more wood (probably seems a bit useless, but helps with late game clutter, not having to rebuild constantly lumber camps, shorter walking distance, etc)
Towers cost -25 stone but +60 wood (not sure about the third bonus, needs testing)
Unique Unit - Khevsur warrior (infantry with mediocre stats like a long swordsman but with a 2% chance for instakill; Elite Khevsurs get 5%)
if that sounds sketchy which on second thought it kinda does, then Khevsurs could be an infantry that heal themselves when attacking (10-20% of damage done - or even more - gets back as hit points).
Unique Techs:
Castle age: Caucasian warfare : regenerating trash (skirms, pikes, hussars regenerate 12HP per minute) 600F 450G
Imperial age: Monaspa (Steppe Lancers get +1 melee armor and +2 pierce armor, also attack 10% faster) 800F 800G (dunno if that isn’t too OP)
Team Bonus:
Outposts cost 10 wood and don’t cost stone; have 2x HP
All that might sound a bit OP for late game but the civ’s overall weakness is towards ranged units. Still needs testing as they sound too OP in late game.
Tech tree
Barracks: militia line up to and including champions
Pikes, but NO halberdiers
obviously NO eagle line
supplies, squires, arson
Archery Range:
Crossbows, NO arbalests
Elite skirms
Hand Cannoneers
Heavy CA withOUT Parthian Tactics
NO thumb ring
Stable:
Hussars
Bloodlines
Cavaliers
Camel Riders (NOT heavy)
Obviously NO elephants
Elite Steppe Lancer
Husbandry
Siege workshop:
Capped Ram
Onager
Heavy Scorpion
Siege Tower
Bombard Cannon
Castle:
UU + Elite UU
Trebuchets
Petard
Unique Techs as mentioned
NO hoardings
Sappers
Spies/Treason
Dock:
Fast Fire Ship
Cannon Galleon NON-Elite
Demolition Ship NOT Heavy DS
War Galley NO Galleon
Dry Dock
Shipwright
Monastery:
Everything except Illumination and Block Printing
Blacksmith:
Everything
University:
Masonry, NO architecture
Stone Wall
Bombard Tower
Ballistics
NO Siege Engineers
Guard Tower (NO Keep)
Heated Shot
Arrowslits
Murder Holes
Treadmill Crane
TC:
Everything (duh)
Mill:
Everything
Mining Camp:
NO Stone shaft mining
Market:
Everything
That being said, there is a lot of testing to be done but I believe it is a fairly balanced civ with its advantages and drawbacks, would love to read your opinion on the matter.