Liatris spicata aka Gayfeather. It grows from corms which are usually moved in either autumn or spring.
https://www.gardeningknowhow.com/ornamental/flowers/liatris/liatris-blazing-star.htm

yes I agree with the above.

Hi, looks like Liatris spicata, they have a tuberous or corm like root, should be divided in spring, so then would be the best time to move it, Derek.

It also goes by "Blazing Star".

Thanks all. It's really so lovely I can't understand why it isn't very common.

I'll add moving it to the list of spring jobs.

Thanks, again.

it is also quirky as it opens from the top down, most flower spikes open from bottom up!