I played on deity as well as the ai+ mod for smarter ai. The mongols started on the same big island as me an rushed me with their mongol horde! watch to see how I fended off the mighty mongols and then went on to take their cities and collect the worlds artifacts and gain a culture victory. If you ever wanted to get a culture victory on deity with Victoria then you want to check this out. You may have to skip over certain parts as i had to step out during the stream a couple of times.