The eastern continent, Saria, also known as the largest piece of land on earth, has always been home to many races and even more tribes. Countries, both big and small, cover the entire land, leaving almost no uninhabited spot on it.
It is unknown who was the first person to call this land the 'largest continent', or the 'eastern continent'. To bestow such titles to a continent, one has to have at least seen one or two other continents, which seems impossible even now, let alone in ancient times when traveling was harder. But the land was named thousands of years ago... Who could have possibly done that? However, not many people cared about such trivial matters. Ever since ancient times, it's been referred to in such ways even if the people living in it don't exactly know how large the other continents are; if there even exists any.