I was there, I saw it.
Probably named Ugg
on the basis of them resembling "cave people" animal hide boots.
Originally made in Australia, probably Victoria, around 30-35 years ago. Climate is reasonably cold in winter, boots very warm in winter.
Sold well, market expanded. Was started by a small home manufacturer, mainstream production then ensued.
Seems to be an adapted and more basic version of the cheap sheep skin flying boots (worn by impoverished motorcyclists).
Can look great as the case may be.
I wear Ugg Boots to keep my feet warm.