league (n.1) Look up league at Dictionary.com
"alliance," mid-15c., ligg, from Middle French ligue "confederacy, league" (15c.), from Italian lega, from legare "to tie, to bind," from Latin ligare "to bind" (see ligament). Originally among nations, subsequently extended to political associations (1846) and sports associations (1879). League of Nations first attested 1917 (created 1919).
league (n.2) Look up league at Dictionary.com
distance of about three miles, late 14c., ultimately from Late Latin leuga (source also of French lieue, Spanish legua, Italian lega), said by Roman writers to be from Gaulish. A vague measure (perhaps originally an hour's hike) never in official use in England, where it is recorded more often in poetic than in practical writing.
league (v.) Look up league at Dictionary.com
"to form a league," 1610s, from league (n.1). Related: Leagued; leaguing.