Born into a famous footballing family, Charlton became a towering centre half at Leeds United where he made a record 629 league and cup appearances over two decades.

He also won 35 England caps and a World Cup winners' medal before succeeding his brother Bobby as Footballer of the Year in 1967. 

'Big Jack' joined Boro in his first managerial role on his 38th birthday. following his retirement from playing in 1973. He reportedly worked without a contract on a salary of £10,000 a year, despite the club being willing to pay much more for his services.

Typically, one of his first jobs was to oversee the re-painting of Ayresome Park in the hope of making it more attractive to fans for the new season, while he would also introduce the famous white band to Boro's red shirts as a marker of identity. 

Bobby Murdoch joined on a free-transfer and slotted into a team largely built by previous manager Stan Anderson. Jim Platt (goalkeeper), John Craggs (right-back), Stuart Boam and Willie Maddren (centre-backs), Frank Spraggon (left-back), David Armstrong (left midfield), Graeme Souness (central midfield), Alan Foggon (attacking midfield), John Hickton and David Mills (forwards) provided the spine for a team which Charlton transformed into champions.

Promotion was secured with eight games remaining of the 1973/74 season with a 1-0 win at Luton Town. The title was won by a 15-point margin, when a win was only worth two points, and Jack was named Manager of the Year. It was the first time a manager outside of the top flight had ever won the award.

Former Leeds team-mate Terry Cooper was the only major signing in the summer of 1974 - Charlton was keen to focus on local talent - and Boro enjoyed a seventh place finish in the top division, only missing out on European qualification on the final day of the season.

Boro finished 13th the following season, but won the Anglo- Scottish Cup, beating Fulham 1-0 in the final, and reached the semi-finals of the League Cup, where Manchester City overcame a 1-0 first leg deficit to win the second leg 4-0.

Jack Charlton through the years

Jack eventually parted company with the club at the end of the 1976/77 season, citing four years as being the optimum time to spend with one group of players and suggesting that the team had peaked - though he would later write in his autobiography that he wished he had stayed longer, believing he could have brought the First Division title to the club with a few additional signings.

He returned to management with Sheffield Wednesday later that year, and he spent almost six seasons at Hillsborough, re-building the club in readiness for what proved to be a return to the top division shortly after his departure.

Jack left Wednesday in early 1977 and returned to Teesside where he took over from Malcolm Allison in March and was charged with keeping the club in the second tier. He was successful in his quest - Boro finished 17th, seven points clear of relegation.

He went on to become Newcastle United manager in the summer of 1984 before becoming the first non-Irishman to manage the Republic of Ireland. He took them to Euro 88 where they famously beat England in their opening game, and they reached the quarter-finals of the World Cup in 1990. He also took the Republic to the Euros in 1992 and the World Cup again in 1994.

Jack, who had received an OBE in 1974, was awarded honorary Irish Citizenship and made a freeman of the city of Dublin in 1996. They were just some of the many honours bestowed on Jack, who was undoubtedly one of the greatest managers ever to have been at Middlesbrough Football Club.