The Uffington White Horse used to be in Berkshire. Then in 1974 it was moved to Oxfordshire in a deal which saw Berkshire gain Slough.
They were robbed! White horse is far better than Slough!
They also lost the ancient county town of Berkshire, which is Abingdon.
As a resident of North Berkshire in 1974 I find it strange that I didn't feel any earth tremors from the movement.
In some sense, however it is still in Berkshire since in my passport it says I was born in Berkshire. The rules state that if the a changed county then the county should be stated as it was when the person was born!