The Premier League used to be called the Football League First
Division but in 1992 the teams in the Premier League branched off
from this championship. There is really no reason that the Premier
League is called the Premier League other than Premier meaning good
and needing to incorporate "League" in the name.
Note that at the moment the Premier League is called the
Barclays Premier League because of sponsorship (Barclays being the
bank.)