in thrall

When the Angles, the Saxons and the Jutes arrived on these shores in the 5thC, they brought with them, among other things, iron collars called thralls.  Not because they had particularly vicious dogs (although they may well have done) but for the purpose of restraining - and establishing ownership of - members of the native population (who had failed to see this threat coming when the Romans finally waved goodbye and left them to it).

The collar would be fixed in place around the neck by a blacksmith and no one who saw it would be in any doubt that the wearer was a slave - in thrall to the whims and demands of a master.  As the polo neck jumper had yet to be invented, escaping while in thrall was a bit of a non-starter, the big iron collar being a bit of a give-away.

Today I am in thrall; this device was placed around my neck at about 9.00am this morning and will remain there until I am eventually freed.  (OK - I unhooked it to take the photo - but we are attached).  It will tell the person who placed it there how my heart is behaving - or misbehaving - and he will eventually decide what is to be done next; more drugs or a bit of mains current.  Either way, I am well and truly in thrall.