What is this plant?

No idea about the plant,sorry .........but is that 4 beautiful Vizslas i spy in your photo?

Hi Hprlady ,this is Centranthus red Valeraian nice plant but a bit of a thug

I also have the white version - great to fill a space but you can cut it back needs some support though and the bees love it.

Yup, Valerian. It's used in herbal remedies, tho can't think what for........? It's pretty, but beware of it getting a grip in walls or paving - the roots are incredibly powerful and will destroy/push apart anything they get their roots into.

Valarian is used as a sleeping medication - sold in health food stores, used for centuries