John, the father of Liberal prime minister William Gladstone received the most compensation for his 2,500 slaves - £85 million, in today's money.
William - PM on four occasions - fought a long and difficult cause for the compensation due to his father and family.
It is significant that the same wealthy families, then as now - make no mention of their slave windfall.
These include virtually all the current aristocracy - and David Cameron's ancestors.
Clearing bank families also did well from the slave proceeds - Lloyds and Barlays, for instance.
Many efforts have been made to obtain compensation on behalf of the slaves.
But successive Tory and Liberal governments have made such actions virtually impossible - bearing in mind the tainted roles of their predecessors.