This slightly wobbly snapshot was pure damn luck and it is not a bumblebee. This is one of the largest bees (20-28 mm) in Europe: a violet carpenter bee (Xylocopa violacea).
This solitary bees are rare. The body is all-black. The abdomen is shiny and hairless. The hind legs are hairy. The wings are glittering in the light in a dark and shiny purple-violet. Very impressive insects but peaceful. They won’t attack until they will be forced.
I was very happy when I specified the violet carpenter bee among 500 different other carpenter bees in a database.