I had the same history teacher as you two! Thankfully, I had exceptionally good teachers for maths, geography, biology and English (guess what my favourite subjects were!). French teacher appalling for four years then had a change (put down from the top set) and learned more in two terms than I had learned in the entire previous four years so got top grade O level. All this in a grammar school too. Only managed Latin because my mum was able to teach me over the summer hols what the teacher only confused me with the rest of the time. And so on.
Absolute bitch of a PE teacher. Really nasty if you weren't one of the favoured.
Most of these 'teachers' had no training – just came straight from uni with a degree. They often ended up teaching a different subject. Not that that mattered if they were 'natural' teachers, but few are.
Things have definitely improved.
And schools are better equipped.