Help With Large Insect ID

[Columbine]

Please could anyone help with an ID for this insect, I have found a couple dead in my conservatory and this live one in the garden. I have been assuming they are huge flies, they measure approx 3cm, but have drawn a blank with an ID so perhaps I am looking in the wrong place?
Being the allergic type I really wouldn't fancy a sting from anything this big, could anyone kindly put my mind at rest and tell me what it is?
Many thanks.

[Gill Catton]

Well the bad news is that this is a horse fly (Tabanidae) but the good news is that really big ones don't tend to be interested in humans, more deer and cows that sort of thing.

[Columbine]

Cheers Gill, thanks for telling me anyway, actually it is bad news as I have two horses grazing in a paddock next to the house which might explain their presence, I have always thought cleggs were horseflies, I'll have to do some homework!
Thanks again.

[Gill Catton]

Cleggs sort of are horseflies, there are lots and lots of different types of what we would call 'horseflies' they're quite interesting in a way, some are very tied to certain species others target a certain area of the body of the food animal. Even amongst the species that bite humans, some legs, others hands/ wrists and another the back of the head etc....

I did a bit of reading about them once during a phase of slight morbid fascination and found them quite interesting actually!

[Columbine]

I've kep horses all my life but never seen one of these before though I do remember my mother in law, a farmer's daughter once telling me that as a child during haymaking, she and the other children had the job of keeping the "horse bees" away from the heavy horses with a swishy stick, I couldn't work out what whe meant at the time but perhaps it was these beasties. Extra fly repellent for mine form now on!