Spawn/Location: 1200 BCE or 800 BCE/Austria (could be either
Noreia [1N of easternmost Alps title] or Vindobona)
Spawn date represents the emergence of Hallstatt culture. The earlier date refers to the proto-Celts of Urnfield culture, while the latter is clearly a Celtic culture.
Leaders: Brennus (stone age), Boudica (classical age), someone medieval?
Color/Symbol: same of the minor civ (Green and Celtic knot)
Expansion stability: Core shifts during the game, similarly to the Phoenician civ. Initally the limited to the
Hallstatt core, then shifts in 500 BCE (La Tène) to Gaul, then shifts to British Isles (when a palace is built there or is 275 CE (end of Gallo-Roman Gallic Empire), finally shifting to Ireland, Scotland and Wales around 500 CE (Anglo-Saxon invasions). Historical areas initially cover all the ones within Celtic maximum expansion (most of Iberia, Gaul, British Isles, Northern Italy, Central Europe, Balkans and Central Anatolia) but are reduced to only Gaul/Northern Iberia by the time of the British Isles core shift. The last core shift turns all Continental European and English areas foreign, with the exception of Brittany and Cornwall that still are Historical.
UP: Power of the Druids: unimproved forest titles beside a city gives + 10% unit production and + 2 culture when worked.
UU1: Galic Swordsman (replaces Swordsman, can be built with cooper, have a free March promotion).
UU2: a medieval unit, possibly Saethwyr (Longbowman, would work quite similarly to Indian Patiodha), Schiltron (Heavy Spearmen) or Gallowglass (Heavy Swordsman).
UB: Dun (replaces walls, gives + 1 culture and free Woodsman I promotion).
UHV:
1)
Europa Celtica: Have 3 cities in Gaul and at least more 3 in any of the following regions: British isles, Iberia, Northern Italy, Balkans and Anatolia in 270 BCE
and have a capital in with refined culture in the British isles by 1CE.
2)
Brennus Legacy: sack or raze two capitals by 280 BCE.
Reference to the historical sack of Rome and the Celtic atempt to make the same in Delphi.
3)
Celtic Christianity: build four Christian monasteries in four different landmasses by 800 CE.
The UHV would allow more activity to the early medieval and offer an victim to Vikings raids. The idea is to represent the Irish missions. Tipically, the four landmasses would be Continental Europe, Great Britain, Ireland and Iceland (refering to the supposed Irish monks that lived there before Viking expansion).
Additional notes:
* We could also re-introduce the Stonehenge wonder. It could have a requirement of being built with x forest titles within the city radious or that it only could be built in landmasses of xx titles maximum (think about Britain) to ensure that the Mediterranean civs could not buid it easily.
* AI Rome would possibly need a conqueror's event to cope with the new Celtic civ. It could be triggered in 50 BCE (Caeser conquest's) and would spawn legionaries in Gaul and Britain (England).
* Many of these ideas were inspired in older comments here in the forum, so I thank all suggestions made until now.