trousers, circa?

[DWFII]

My tailors, Meyer and Mortimer, on Sackville Street in London, were the tailors of Beau Brummell. They made his trousers, and it was Brummell, I am told, who popularized this innovative fashion and made them all the rage.

Thanks for taking the time...

Is that the first occurrence of trousers? And what is the date?

What was worn before that?

I am thinking trews and trousers are somewhat contemporaneous...??