i got this identified by the foliage as larkspur earlier on, but now that it's flowered, which one is it?
It's Consolida ajacis Lil. The modern 'series' have a much more crowded flower spike so it's probably from an older series or close to the wild form
it's possibly a wild one then as i didn't sow any!
They aren't native here Lil, it may have come from a patch in another garden that has had Larkspur seeding for a few years.