12/15. And one of the ones I missed was a wrong click (I *knew* which King was defeated by Oliver Cromwell, drat it!). Amusing, since most of my knowledge of British history is from casual reading.
But I think it's more that not everyone is interested in history. I find it interesting, so I pick things up. But when visiting Britain I was alternately surprised by the depth of some people's knowledge of their local history . . . and the total lack of knowledge others cheerfully admitted. I always suspected the latter were playing fool-the-Yank, though.