Please answer a question about the following article about Armenians:

Armenians have had a presence in the Armenian Highland for over four thousand years, since the time when Hayk, the legendary patriarch and founder of the first Armenian nation, led them to victory over Bel of Babylon. Today, with a population of 3.5 million, they not only constitute an overwhelming majority in Armenia, but also in the disputed region of Nagorno-Karabakh. Armenians in the diaspora informally refer to them as Hayastantsis (Հայաստանցի), meaning those that are from Armenia (that is, those born and raised in Armenia). They, as well as the Armenians of Iran and Russia speak the Eastern dialect of the Armenian language. The country itself is secular as a result of Soviet domination, but most of its citizens identify themselves as Apostolic Armenian Christian.

Who founded the first Armenian nation?
Hayk