Sir Alexander Matthew "Matt" Busby is the longest serving manager in the history of Manchester United, ahead of Sir Alex Ferguson, although Ferguson has overseen more matches as manager.

Before going into management, Busby was a player for two of Manchester United's greatest rivals, Manchester City and Liverpool. During his time at City, Busby played in three FA Cup Finals, winning one of them. Busby made one official appearance for Scotland against Wales at Ninian Park in 1933. After his playing career was interrupted by the Second World War, Busby was offered the job of assistant coach at Liverpool, but they were unwilling to give him the control over the team that he wanted and he took the vacant manager's job at Manchester United instead, officially taking the reins on 1 October 1945.

Busby immediately put his mark on the side, leading them to the runners-up spot in the league in 1946-47. Manchester United were runners-up in 1947, 1948, 1949 and 1951, and won the FA Cup in 1948, before winning the league championship in 1952. By this stage, Busby started to rebuild an ageing side with youngsters.

During this period, the team picked up the nickname the Busby Babes due to the youthfulness of many of the players he fielded. They won the league in both 1956 and 1957, and were runners-up in the 1957 FA Cup Final.

Sadly, on 6 February 1958, on the way home from a European Cup tie against Red Star Belgrade, seven players and three club officials were among the 23 people who were killed at in a plane crash at Munich Airport. Busby suffered multiple injuries and twice received the Last Rites, but he recovered from his injuries and left hospital after two months.

After the crash, Busby built a new side around the Munich survivors and by 1964 discovered the talents of George Best.  In 1963, Busby had successfully rebuilt United as he guided them victory over Leicester City in the FA Cup final. They were league champions in 1965 and again in 1967, with only a defeat on the final day of the 1967-68 season stopping them from recording a rare championship hat-trick.

The biggest success of his career came on 29 May 1968 when the team won the European Cup. He retired as manager a year later but remained at the club as a director, handing over managerial duties to trainer and former player Wilf McGuinness. When McGuinness was sacked in December 1970, Busby briefly returned to his managerial duties. Busby was awarded the CBE in 1958 and was knighted following the European Cup victory in 1968, before being made a Knight Commander of St Gregory by the Pope in 1972.