Help needed identifying a fruit

[superfly78]

Hi,
I came across this tree in the woods by me and was wondering if anyone could tell me what it is. The fruit seem too big to be damsons but too small to be plums. The skin was purple with a bloom on it that could be wiped of and the flesh was green and tart/astringent which i'm not sure whether was due to them being under-ripe or because they are damsons after all.

[Thelma Sanders]

The plum family crosses easily between bullace/damson/plum .....so just think of it as a wild plum

Nice find

[starloc]

They look just like the plums we have here in Bulgaria , one of the 3 or 4 main types grown here, just called `prune` by locals , its a blue one used in the past to dry to make prunes across Europe

The names of fruit are a bit silly here!
Blue ones here that shape are Prune.....
Yellow round ones (cherry plums) are called Rakia.....

The blue ones here look like yours and look very like a Hauszwetsche German prune

[lottie dolly]

I believe they are called a damzeen,not sure off the spelling,most peeps refer to them as plums,it is just a smaller plum,they make lovely jam,the taste is a strong plum,