The White-letter hairstreak is named from the white streak that runs through its wings. You can see it forms a sideways letter 'W'. They are quite similar to the Purple Hairstreak but as well as bing a darker more brown colour, the orange "eye' spot on the Purple Hairstreak is more of a continual zig-zag pattern on the White-letter Hairstreak.
They normally live on elm trees, drinking the honeydew from the leaves. Although I had been looking for them on elm trees for a while, I stumbled across several while I was walking through the woods at the south of the estate. There are several sunny areas along the path, that are very popular with butterflies. These were just on leaves in the hedgerow, but no doubt there was a hedgerow elm nearby.
