They look like either Cornflowers or Bachelor buttons.

Knautia common name here is scabious. There are several named varieties or the pale lilac native one.

It was a seed weed in our previous garden, so if you want more.....sow the seeds when ripe.

Knautia macedonica, to be precise...

Thanks a million for the responses. Have a large area with ground elder so need something that will grow above it and these are ideal. Thanks again.

Don't forget to cut the flower heads off the Ground elder, unless you have completely given up on it and don't care about all the seeds.

Knautia macedonica can be prone to mildew. However there is a shorter form, K. m. 'Mars Midget', which rarely suffers from it

Goldfinches love the seed heads 😊