1418
"No nation is older than 250"
(lemm.ee)
Transcript
A threads post saying "There has never been another nation ever that has existed much beyond 250 years. Not a single one. America's 250th year is 2025. The next 4 years are gonna be pretty interesting considering everything that's already been said." It has a reply saying "My local pub is older than your country".
HBC was effectively a "country" for a good chunk of time as well. It had full autonomous control of the land, it's own 'government', provided public services, policing, and it's own military.