Tabanus sudeticus

Or dark Horse Fly - we think ! It is in the family Tabanidae, in the order Diptera. It is about 1” in length.
We have had some tree surgeons cutting back broken branches this morning behind our fence, and whilst we were all having a cold drink, this visitor arrived and landed on the equipment. They have gone now, so we live in hopes this little visitor has gone as well as if I get bitten by the odd horsefly everything swells up!!!!