10 Most Fearsome Rivalries In World Football
4. Rangers - Celtic / "The Old Firm"
Without doubt Britains most impassioned clash, the Old Firm derby is known throughout the sporting world as one of the games most politically-charged fixtures.
Pervaded with centuries of religious conflict between the Catholic (Celtic) and Protestant (Rangers) sections of Glasgow, the Old Firm derby has always been a hub of sectarian and civic dispute. Contests between Scottish footballs two most successful clubs have more often than not resulted in violent outbursts which has made the fixture evermore notorious.
Heavily infused by partisan chanting, confrontations between the republican Celts and the loyalist Rangers support are a recurrent feature of this particular rivalry.
And although serious incidents of violence within this fixture has reduced significantly in times gone by, the Old Firm derby remains one of the most vociferous and politically-disputed in football with such strong ideological differences dividing the two sets of supporters.