https://en.wikipedia.org/wiki/Hugh_Grosvenor,_7th_Duke_of_We...
> Upon his father's death, in August 2016, as well as the peerages, he inherited a wealth currently estimated at £9 billion, with considerable trust funds for his sisters. This wealth is held in a trust, of which the Duke is a beneficial owner but not the legal owner — an arrangement which received considerable press attention due to the inheritance tax exemption this confers.
The standard Inheritance Tax rate is 40% in the UK when above a certain threshold - https://www.gov.uk/inheritance-tax
Seems fair!