Until 2000, the value of medals for gallantry was liable to be included in estates for inheritance tax purposes, and only in 2014 was the value of other awards made exempt from IHT.
There is also an exemption from Inheritance Tax for the estates of those that die as a result of active service, even if the death occurs many years later, so long as the death is related to an occurrence on active service. So, if the Duke of Westminster had been mobilised for Herrick and succumbed, his massive estate would have been passed on free of IHT. As a tax planning strategy though, it is a bit extreme!
More recently, this has been extended to the emergency services.