One of the towering figures in post-war British football, Joe is revered as a true Blue City icon and also stands as one of the most pivotal figures in our storied 125-year history.
As such, he is an essential building block of our very DNA and took charge of the Club on this day in 1965.
Joe, of course, was the man who – in tandem with visionary coach Malcolm Allison - presided over one of our most fondly remembered golden eras which spanned from the mid-sixties through to the early seventies. A period which helped truly put City on the global map.
A gifted and visionary manager, Joe helped assemble one of the most thrilling squads to ever grace English football, bringing together a side which helped up light up the game and was the very on-field embodiment of his positive, outgoing optimistic nature.
Just as genial Joe always looked on the positive side of his life, so his players helped bring smiles and joy to that generation of City fans fortunate enough to have witnessed them in our pomp.
Colin Bell, Francis Lee, Mike Summerbee, Neil Young, Tony Book, Mike Doyle to select just a few… the names still roll off the tongue now more than a half a century on, such is the pull, enduring impact and lasting legacy of that multi-talented City ensemble.
The Maine Road team moulded by Mercer went on to secure a plethora of silverware during that dizzy period, lifting the Division One title, FA Cup, League Cup and European Cup Winners Cup within two years, a fitting testament to Joe’s powers of inspiration and unique man-management skills.
The taste of silverware was nothing new to Mercer however.
Prior to taking up the Maine Road reins in 1965, he had enjoyed an illustrious and hugely successful playing career.
Born in Ellesmere Port in 1914 the son of a former professional with Nottingham Forest and Tranmere, also called Joe, talented left-half Mercer had joined Everton in 1932 and went on to make 186 league appearance for the Toffees, being part of the Goodison side that secured the 1938/39 first division title.
Mercer also won five England caps in that time before his career – like that of so many others – was interrupted by the onset of World War Two.
Following the end to hostilities, Joe subsequently moved to Arsenal in late 1946 for a fee of £9,000 and, despite having turned 32, he was to enjoy even greater success with the Gunners.
Appointed captain, Joe was to lead Arsenal to two league titles (in 1947/48 and 1952/53) as well as FA Cup glory in 1950, eventually making 247 league appearances before his eventual retirement from playing.
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It seems remarkable looking back now but, in the immediate aftermath of his retirement, Mercer spent the best of a year working as a grocer – Joe also ran his own grocery business in Wallasey - and aspiring journalist before taking up the reigns in a management.
After an initial challenging spell at Sheffield United where he suffered the blow of relegation, Joe soon moved on to take charge at Aston Villa where he again initially suffered the indignity of seeing the Midlands club drop out of the top flight in 1960.
However, within a year a vibrant, attacking Villa side – a portent of what was to come at City – were back in the big time.
Unfortunately, Joe struggled with illness during his time at Villa Park, and left the club while recuperating at home in 1964.
Fully recharged and rejuvenated, one year later, Joe took charge at City, with the Club at the time struggling in the Second Division.
One of Joe’s first tasks was to install the up-and-coming Malcolm Allison as his assistant, tasking the Londoner with the more rigorous day-to-day coaching duties.
It was to be the first of many inspired moves on Mercer’s part
Equally astutely, future legends Summerbee and Bell were both recruited in Mercer’s first year at the City helm.
And the rewards were soon forthcoming with City crowned as Division Two champions in 1966.
Mercer continued to strengthen his City squad, bringing in powerhouse striker Francis Lee from neighbouring Bolton for a club record £60,000 fee.
Franny's arrivals proved another crucial building block in what famed BBC commentator Kenneth Wolstenhome described as ‘the most exciting team in England’.
And within two years, Mercer had led City to the summit of English football, a dramatic 4-3 win at Newcastle in May 1968 clinching the Division One title – our first top-flight crown in more than 30 years.
It was the start of an unprecedented period of success with City plundering a plethora of prizes with Mercer at the helm and trusted and lieutenant Allison at his side.
A thrilling FA Cup triumph came our way in April 1969, Neil Young scoring the decisive goal in a 1-0 triumph over Leicester City as City lifted the trophy for a fourth time.
Our Wembley win also saw Mercer carve his name into history.
For it meant he became the first man to have won the league championship and FA Cup as both a captain and a manager, having achieved the feat during his Arsenal playing days.
Two more pieces of silverware were to follow in 1970.
First, City overcame West Bromwich Albion to win our first-ever League Cup crown, full-back Glyn Pardoe sealing a dramatic 2-1 win over the Baggies in extra time on a mudheap of a Wembley pitch.
One month later, Mercer orchestrated yet more success, this time on the European stage.
A Francis Lee penalty was enough to secure the European Cup Winner’s crown as we edged out Polish side Gornik Zabrze 2-1 in the final staged in Vienna after Neil Young had earlier opened the scoring.
Sadly, that was to prove the final prize of the memorable Mercer era.
Boardroom issues saw Joe leave the Club in the summer of 1971 with Mercer then taking charge at Coventry for two years before he eventually took up a role as director with the Midlands outfit.
However, in the autumn of his career, Joe was also to enjoy a brief and distinguished spell as England caretaker manager.
Following the resignation of Sir Alf Ramsey in late 1973, Joe took charge of the national side for seven games in 1974.
And his impact was instant as he led the Three Lions to British Home Championship and only suffered one loss in seven games before Don Revie was appointed full time manager.
After a happy retirement spent with his beloved wife and huge City fan Norah, Joe sadly passed away aged 76 in 1990.
But his impact and enduring legacy on both City and the wider game will never, ever be forgotten.
For Joe Mercer's life and achievements are truly the stuff of legend.