Every summer, for two to three weeks, male horseflies are to be seen in the garden hovering motionless, often only a foot or two above the ground. They are also common along the rides of the adjoining woodland. Photographing them is a challenge as they tend to locate themselves using nearby objects, and will remain a fixed distance away (too far) from an approaching camera lens. Years ago I identified them from an ancient natural history book as Tabanus distinguendus. But names change, and this may have been wrong in the first place. Can anyone put a name to this fly from the photos (taken years ago on film).
Tabanus distinguendus is now known as Hybomitra distiguenda, the Bright Horsefly. Your photo shows a female (the eyes would meet above the head if it was male), and I can't see any reason for it *not* to be H. distinguenda, but I'm afraid I'm not confident of identifying Hybomitra species from photos. Ideally I'd want to see more of the face from the front, and the sides of the abdomen.
So, probably H. distinguenda but I can't confirm that for certain.