From my reading, not researched personally, 'blue jean' has been carried in various navies ships for a long time, specifically to give/sell to the matelots for trouser making. Certainly it was in the Royal Navy (when they weren't at war with France), and quite likely since before there was a United States, let alone a Levi Strauss.

You can patent anything if you get in first, as drug companies are doing, searching the world for local herbal remedies to steal and patent. Heard about that on the Beeb overseas service.

'Jeans' in the UK when I was young. 'Denims' I remember as an alien name from the USA.