Seven miles off the rugged west coast of Ireland a wild fang of an island juts out of the sea. Its sheer flanks are uninhabited for all sane reasons. Only seabirds live here, and only in summer, when the fierce North Atlantic storms have subsided. But to thirteen men this was just the place.

Sometime in the late 6th century, after Rome fell and the continent plunged into a barbarous age, a band of Irish brothers paddled for five hours in a small handmade boat to reach this island. They ascended the eastern slope, and near the brink, on the leeward side, they built stone huts and called the place home.

They were monks and they seemed struck with madness.

...