Arrows, mines, and Englishmen
3600 B.C.: Celtic explorers discover primitive bows in an ancient ruin, and quickly put them to use.
Of all the things I could have found in a ruin, this is one of the best. My explorer turns into a free ranged unit, which are super valuable at this point in the game.
Later that year, the Celts come into contact with the English tribes near their settlement of London. Something gives them a bad feeling about these guys...
Ah, so it seems I spawned next to one of my real-world historical rivals. Given my planned strategy, I will likely be waging war on them before long. There will be time for peace and scientific advancement once the Medieval age rolls around. For now, I will meet every new civ as a potential foe, and therefore a potential source of Faith.
3575 B.C.: The Celts begin mining with primitive, stone tools.
My first tech! This will allow me to build mines, which will increase the productivity of my cities with mineral resources.