Purple dead nettle, Lamium purpureum. Or its closely related cousin, henbit (they look very similar and both appear at the same time).

Pulling them, manually weeding them out, is very effective if time consuming. Or you can treat with most broadleaved weed killers. But be careful if using in amongst desirable plants as the weed killer will not differentiate :-)

The purple deadnettle is closely related to the henbit, which is often referred to as the henbit deadnettle. The green henbit leaves are kidney shaped and are attached directly to the stem, whereas the purple deadnettle has a triangular shape, and the stalk is attached to the stem’s leaf blade.

https://www.ediblewildfood.com/purple-deadnettle.aspx

Henbit is easily confused with Purple Deadnettle (L. purpureum), which has petioled leaves all the way to the top leaves. The middle and upper leaves of L. amplexicaule (Henbit) do not have petioles.

https://www.ediblewildfood.com/henbit.aspx

L purpureum. 100%. Take a look at images of both species. They're visually quite distinct one from another. In lay terms Henbit has more scalloped leaves and more tubular flowers which stick out at the top of the flower stem. In my neck of the woods Henbit is quite unusual. I rarely see it. I get the impression it's commoner in the USA.

clean an area ... and then properly mulch the area... and keep an eye peeled so it doesnt return and seed on top of the mulch .. ken

My favorite to share in spring: http://identifythatplant.com/three-easily-mixed-up-early-spring-plants/

As both purple deadnettle and henbit are weeds and should be removed ASAP, I find differentiating between the two pretty much unnecessary. Go ahead and make the effort if you want to be precise but for most home gardeners it is enough to know that these look-alikes are just weeds destined for removal :-)

I like fatamorgana's link, but it is much harder to mistake ground ivy/creeping Charlie for one of the lamiums :-) I don't find it to be at all similar other than weediness and approximate flower color.

Having been on or having led more than a few guided walks, I know how many people struggle to ID more than a dandelion. While the 3 plants don't confuse any of the regulars here, it would be more than many Americans could handle with regards to identification because as a whole they just don't know, nor do they care to, much about plants. The people asking and answering here being marked exceptions in interest and knowledge.

Personally, I can see where it would be confusing for some as they are plants of similar habit (low and weedy) plus very close bloom times and flower color. In fact, all three bloom at the same time in my gardens often side by side. ;)

Thanks all for the help and advice. I’ll get my knee pads on, weeding tools and soft mindful weeding music. Weeding can be very soothing.

It certainly can. It's also a really good way of learning more about your garden. Hand weeding is a great way to learn plant identities, especially at the seedling stage.