2500 years ago. There was neither Nepal or nepali. Gautam buddha didnt speak nepali nor did he eat dal bhat. All we can say, the place he was born is located in PRESENT day Nepal which nepali seems to take a lot of pride. He didnt try to get popular or represent nepal at all.. All he cared about was human suffering and left us a path to follow that might help us live peacefully and in harmony. I think its useless trying to claim buddha was born in nepal, he is a nepali and represents nepali pride. Theres more to focus on. Also, buddhist already know the site buddha is born and go to lumbini to pay homage. For others not interested in religious practices, its just a topic to fight about i guess. A moot point