About my first comment:
In one of my early games (probably my third), i was playing as Rome and i was sharing a continent with India. Ijust got Chivalry and i was an industrial power so i declared war. I got one city, then all of these War Elephants came in. I now know that they are the same as knights, but they were so BIG! It took fifteen to twenty turns to turn back to the offensive (after they ran out). After that, i was much more confident, but when even a single one attacked, it did some damage.