[2][3][4][5] Mercer was born in Ellesmere Port, Cheshire, the son of a former Nottingham Forest and Tranmere Rovers footballer, also named Joe.

[6] His father died following health problems resulting from a gas attack during the Great War, when Mercer was only 12.

Mercer made 186 appearances for Everton, scoring two goals and a winning a League championship medal in the 1938–39 season.

During the war, Mercer guested for Chester City, making his debut in a 4–1 win over Halifax Town in September 1942.

As captain, he led Arsenal through their period of success in the late 1940s and early 1950s, helping to haul his side from the lower end of the table to win a League championship title in the 1947–48 season.

On 10 April 1954, he broke his leg in two places after a collision with teammate Joe Wade in a match against Liverpool, and finally called time on his footballing career the year after.

In his first season at Maine Road, the club won the 1966 Second Division title to regain top-flight status.

[4] In the 1970–71 season, Mercer had a dispute with his assistant Malcolm Allison, after the two men became embroiled in Manchester City's takeover battle.

During the same time, Mercer was also caretaker manager of the England national football team for a brief period in 1974 after Sir Alf Ramsey's resignation.

During his time in charge, England won the 1974 British Home Championship title which was shared with Scotland.

The FA was so impressed by these performances that questions arose about the possibility of Mercer taking the job on a longer-term basis, with, as an assistant, his Coventry City protege Gordon Milne.

Mercer, too, seemed open to persuasion but the FA was working on another plan, putting out feelers to the most successful English club manager available, Leeds United's Don Revie.

[15] She died in March 2013 and her funeral was attended by 120-plus mourners, including City legends Mike Summerbee, Tony Book, Colin Bell and Joe Corrigan, as well as Bobby Charlton.

On the road, there are two mosaics by renowned Manchester artist Mark Kennedy of Mercer; one shows his smiling face lifting the League Championship trophy; the other is a version of a famous photograph showing the back of him as he looks out over the Maine Road pitch towards the Kippax Stand.