The founding of Dublin
2775 B.C.: The Celts finally get around to inventing pottery, mainly to decorate with depictions of their warriors kicking the crap out of Frenchmen.
2675 B.C.: Celtic villagers east of the River Celtica found Dublin, the second major Celtic settlement.
This is somewhat late in the game to get my second city, and I really need a breadbasket. Building near these plains and a wheat resource will allow me to engineer a population boom, while still retaining the Faith bonus from having adjacent forests.
Later that year, the Russians make a declaration of friendship that further cements the Celtic-German-Russian League.