It's called Nigella and often called "Love in a mist" in the UK

Badfish is right. It will seed itself everywhere so if you don't want that then pull it up. It is very pretty though.

i love it. Wish it would self seed in my garden but it never does!

Quite agree, Karen! I have sown it from seed more than once, but it has always disappeared after the first year!

Great! Thank you so much!!!!

Oh, Pika..forgot to say. Last year I dried the seedheads and sprayed them silver for a winter/christmas floral arrangement.