To borrow a phrase, football makes strange bedfellows. It is not entirely uncommon for a manager to lead one club for years only to depart for said club’s principal rival, at times irking supporters on both sides of the divide. Some have become so adept at hopping into the enemy’s bed though, they feel no compunction about doing it a couple times, as Harry Redknapp demonstrated last decade by leaving Portsmouth for Southampton only to make a return engagement with Pompey. The jowly one returned to his “spiritual home” at Fratton Park before sailing away from the south coast entirely for his current sojourn in North London. German manager Felix Magath has helmed seemingly every club in Bundesliga, including both sides of the Nordderby as he began his career at Hamburg SV only later to manage its derby rival Werder Bremen.

For Manchester though, the trenches are troweled so deeply and layered with barbed wire so ominously only one brave soul appears to have dared to march across the city and shift allegiances from red to blue. Perhaps it has come about because Matt Busby’s legend has cast all who came before him in shadow, or perhaps it is because his direct family line was lost sometime in the 1960s, but Manchester United and later Manchester City manager Ernest Mangnall seems lost to history.

It seems a pity, as Mangnall was the Busby of his day–having managed United’s first major titles and cups in the early 20th century before departing Old Trafford in an attempt to achieve similar success at City’s old Hyde Road grounds. Following his move into Manchester proper, United endured its longest barren stretch of glory while Mangnall sought to keep City operational during and after World War I. While Mangnall was never quite able to establish blue as the winning colour for the city, his contributions to the histories of both clubs cannot be denied, even if it is a tad difficult to track down today.

The largest and most obvious monuments to his memory, however, are Old Trafford and formerly Maine Road. Mangnall was a part of management when United built and moved into Old Trafford when it was still brand new. When he switched over to Manchester City, it is said he was instrumental in the Citizens’ move to Maine Road after a fire had damaged the Main Stand at Hyde Road in 1920. In short, Mangnall built talented squads for both red and blue, instilled winning ways for each, and had a hand in both clubs constructing and playing in their historic home stadiums. To put the legend of Mangnall in contemporary context,  consider if Sir Alex Ferguson had left Old Trafford in the early 2000s to help City move into its new City of Manchester Stadium and lead them to glory while the Glazer family defaulted United into a cup-less funk.

There wouldn’t have been enough rotted fruit in all of England to throw at Ferguson on derby days.

Born in nearby Bolton in 1866, Mangnall began his managerial career at Burnley, but encountered little glory at Turf Moor. Mangnall managed the Clarets to relegation from the old Second Division in 1903, and despite successful re-election to the Football League, chose to leave Burnley for the reclamation project going on at Manchester United. Bear in mind, this was a United that had just dropped their Newton Heath name, were struggling rivals of Burnley in the Second Division after having been relegated from the top flight, and only a year previously had to fight off a winding up order just to remain in existence. Renewed investment by local Manchester businessmen such as John Davies kept the Red Devils alive, and Mangnall became their 3rd secretary (manager not being the occupational nomenclature of the day) to attempt promotion to the First Division.

Mangnall’s third season saw United finally playing in the top flight again and he helped fill the club’s cob-webbed trophy cabinet. United won the First Division in Mangnall’s fifth season with the club, and he managed silverware in all but one season thereafter. Having won two league titles, an FA Cup, and the first FA Charity Shield, he opted to dump United for rival City in 1912. Strangely enough, it appears his final match managing United was in the Manchester derby of September that year. From historical references in Gary James’ book Manchester–A Football History (2008) it was reported in the local newspapers that there was a wry smile to be found on Mangnall’s face as his Red Devils were beaten 1-0 by his new City employer. In terms of the Manchester Derby, it was only United’s second loss to the Citizens under Mangnall’s tenure–the other having occurred six years prior.

Now, what is rather odd about Mangnall’s move to City is that, only a few years before, he poached a number of City’s more talented players who in turn were the core of his first title-winning squad. Draconian penalties following the Billy Meredith scandal, had allowed Mangnall to buy up the best Manchester City players like Sandy Turnbull, Jimmy Bannister, and the Welsh Wizard himself at auction well below market value. Having built a juggernaut of a squad with the finest talent of his city rivals, Mangnall chose to undergo a new reclamation project at Hyde Road.

Perhaps because he had previously assisted United in stripping City of its talent, Mangnall was able to win a few league matches for the blue half of Manchester but was unable to replicate his cup collecting habits. His derby record managing City was a somewhat respectable 3-3-4, and he compiled an overall record of 151 wins in 350 matches for a 43% win rate with City. Although no league games were played from 1915-1919 due to the ravages of a world war threatening to wipe out an entire generation of youth, City continued play in regional War associations. Mangnall directed them to a winning campaign every year and three 1st placed finishes in seasonal tournaments. When league play resumed in 1919 Mangnall led them to seventh before managing City to second position in 1920–equalling its highest ever First Division position.

Following defeat to Newcastle United in the FA Cup semi-finals, Manchester City opted not to renew Mangnall’s contract, and the long-serving manager of both City and United hung up his whistle in 1924. It is telling that by the second season after the Blues let Mangnall go, they were back in the Second Division following a disastrous 1925/1926 campaign that saw the Citizens ship one hundred goals against only thirty-five scored. While Manchester City recovered somewhat quickly post-Mangnall to win the First Division in the 1936/1937 season, it took Manchester United considerably longer to regain its place amongst England’s elite. Not until Busby triumphed in the 1951/1952 season was Manchester United finally able to add another league title to the trophy cabinet Mangnall built and filled at Old Trafford.

Today, under the armfuls of accolades collected by Busby and later on Sir Alex Ferguson, Mangnall’s success and impact upon United might be missed. When one considers how generic United was before his arrival and how it struggled for much of the early 20th century following his incredible choice to swap red for blue, there might be no United without him. As for City, without Mangnall’s leadership during difficult years of world war, there might not have been a Manchester City for Arabian sheikhs to purchase as a rich person’s play thing. As we will see in the FA Cup semi-final, City and United will eternally be at odds, but there is one common truth their supporters share.

Ernest Mangnall is a Mancunian legend.