Until recent times, the institution of slavery was almost universal, as was its handmaiden, the slave trade. Nearly all societies outside Western Europe practised it in one form or other and some still do. The Europeans themselves, of course, notoriously made large fortunes both out of the Triangular Trade and slave-manned plantations in the New World. When slavery was abolished in British possessions overseas in 1833, the owners that Parliament compensated included the very rich, but also maiden ladies of modest means, so deeply ingrained was the “peculiar institution “ in the British economy.
The PM’s big day was spoiled by a predecessor who will have known exactly what he was doing.