Purple

Gosh it was hot today, i thought yesterday was a scorcher!  Thunderstorms in the afternoon which hound did not like!  Still I won't have to water any plants this evening.  The slugs & snails decimated my cosmos plants but touch wood, the newly installed scented leaf geranium and heucheras are resisting the blighters.  We used to have hedgehogs which kept the slimy population down.  The foxes don't seem to have the same effect.
This flower grows everywhere, the bees absolutely love it so it's staying.  It grows to a little over a metre in height with these flower spikes atop the long stalks.  Anyone know what it is?  Miranda?