We bumped into an acquaintance there. John and his wife live on a ridge top, off the grid, which puts them in both forest-fire and lightning zones. They know that.
He said that a recent lightning strike exploded a big pine tree near their house. Along with the tree (and some baby rabbits), the strike fried their generator, inverted, and on-demand water heater — and of course it meant that they could not pump water from their well.
"We were back in the Stone Age!" he said.
It got dark, they wanted to read and play chess (they are serious about chess). What to do? Being a handy sort of guy, John rigged up a bank of LED lights with a 12-volt battery. It was too bright, his wife said.
But he could have made rush lights, if he had started a little earlier.
It bothers me to see movies and TV shows set in the past where there are masses of (petroleum-based) candles blazing away. Like the HBO series Vikings —by Thor's ring, they had so many candles that they must have brought them back from their raids by the longship-full. Kings could not afford so many candles!
But what the common people had were rush lights, as demonstrated in the video clip above. You have to overlook the non-medieval heat gun. The Brits are getting really absurd about safety issues.
So there you have it. Find some pithy grass and soak it in animal fat. Hold it in some kind of clip or support, and you have light, without the need to raid an abbey.