The competition between the Reds of Manchester and Liverpool has become almost unique in its intensity since the Premier League's balance of power shifted along the East Lancs Road in the early 1990s, as Sir Alex Ferguson set about his agenda of returning the club to the standards set by Sir Matt Busby and his fabled Babes.
Such is the determination for domestic dominance, the true glory of United’s 2010/11 title triumph - a record 19th - was widely recognised for its impact on the local hierarchy. The facts are simple; the Manchester Reds are now officially the most successful club in England.
Famously, tensions between the cities originate from industrial matters stemming back to the building of the Manchester ship canal in the 1880s, which bypassed the port of Liverpool and led to job losses on Merseyside – a decision that is still bemoaned on the Mersey Ferry tour.
“The thing about us and Liverpool is the rivalry - they are the most fantastic games,” Sir Alex said last term. “They're unparalleled in British history in terms of the success of both clubs and that's why we need each other. The way industry changed when they opened the ship canal is all to do with it.”
The rivalry between clubs, however respectful, is also demonstrated by the fact that no player has transferred directly between them since Phil Chisnall left United for Liverpool in 1964. Gabriel Heinze tried to follow the same route in 2007 but was instead sold to Real Madrid.
Of course, matters on the pitch have diluted the relevance of this historic North West derby in recent years, given that Liverpool have not won the championship since 1990 and realistically look some way off doing so, which has led some to point to City as a more prominent and worthy adversary.
Intriguingly, Salford-born Paul Scholes, a player whose down-to-earth manner is celebrated on the terraces, remains unsure which of our competitors warrants the title of 'biggest rivals' when quizzed on the matter in January's edition of Inside United.