This is what a well-behaved Plum should look like. Purple-leaved Cherry Plum, Prunus cerasifera 'Atropurpurea' at Dinmont and Talisman, March 27, 2021.
I think this is a plum, but I don't think Prunus cerasifera, which you've helpfully just shown above. Maybe Prunus spinosa (Sloe, Blackthorn)? It looks like one of the Prunus domestica photos at Prunus domestica ssp. domestica (plantsam.com). I had to convince myself that it isn't Amelanchier - thanks for including the bark photo and the blossom photo that shows the rounded sepals and round buds growing from the branch, not in an inflorescence. On that page I linked to, there's an Amelanchier photo that shows very similar-looking flowers. At least now I think I've learned what they look like. We could use some help here. Lots of people probably recognize this thing.
Here are photos of Prunus spinosa blackthorn or Sloe taken this morning. They are in flower everywhere here in the South of England atm. Perhaps @Anne Eng can compare. The tell tell feature if not sure are those 2" long thorns that can rip into skin if not aware of them. Last photo refers.
That doesn't look the same to me. The petals on Anne's photos are so long and narrow that they led me to doubt at first that they were plum blossoms. Thanks, Acerholic.
After painful and rainy investigation through the underbrush, I couldn't see any thorns on what I shall call the Napoleon Plum. Here's what the Blackthorn Plum looked like at VanDusen in 2013: those thorns are very visible. I think Wendy is right. Napoleon does look like it could be Prunus domestica, plain old Plum.
The petals look more like Prunus americana, from photos I'm seeing, but I see that they are supposed to be in umbels, so that should rule this out. And I don't know if we have those around here.
Whatever it is, I found what I think is the same today too, on Wesbrook a little north of Chancellor. This one has some open leaves, and some unrolling ones. Since the tips are not pointed, it looks like we can rule out Prunus americana. So P. domestica, unless someone tells us it's not. The homeowner came out while I was there, said she has never noticed fruit, thought it was an ornamental. There were some, but not many, groupings of two or even three stems in what looked like an inflorescence. My photos were not even close to being in focus, so I can't show you.