It’s a little hard to get your hands on, but if you can find Muirchu’s Life of Patrick, I heartily recommend giving it a read. It reads like a hagiography written by one of those people who thinks a narrative version of his and his buddies’ Dungeons & Dragons campaign would be the coolest idea ever for a novel.
It’s available right here! http://www.confessio.ie/more/muirchu_english
Brilliant!
Now I just have to take a look at that.