There are many places where it is considered amndatory to tie off as soon as you are either one lift up on a scaffold (aproximatly2m) or as soon as you are off the ground, regarless of height.
We wore a safety rope on our belts in the late 70's in industrial construction, but the rule was not inforced until about the mid 90's IIRC.
If someone asked for a safety harnes back in the day we would not put them into the air , thinking they were scared!!
However, as far as the history of when it was first implimented, I am not sure.
Cat