You're thinking of Somerset v Stewart here (I'm pretty sure). And, one, Somerset's case didn't actually say no one on British soil could be a slave; that was the argument that was made by the anti-slavery lawyers, but the actual judgment just said that the slave's owner couldn't force him to leave the country. And two, Somerset overturned the existing legal opinion at the time, which held that slavery was completely legal in England. So... before Somerset, it was absolutely possible for slaves to exist on British soil, and there were in fact slaves on British soil.
It is true that they weren't a major feature of British life, the way they were in the colonies, but "no slaves in Britain" is really not correct.
no subject
You're thinking of Somerset v Stewart here (I'm pretty sure). And, one, Somerset's case didn't actually say no one on British soil could be a slave; that was the argument that was made by the anti-slavery lawyers, but the actual judgment just said that the slave's owner couldn't force him to leave the country. And two, Somerset overturned the existing legal opinion at the time, which held that slavery was completely legal in England. So... before Somerset, it was absolutely possible for slaves to exist on British soil, and there were in fact slaves on British soil.
It is true that they weren't a major feature of British life, the way they were in the colonies, but "no slaves in Britain" is really not correct.