During this period, Stein developed his skills as a coach and was offered the job of staff coach to the Celtic youth squad, but the position held no ambition for the big man, and in 1960, he soon found himself with the paradoxical challenge of rescuing Dunfermline FC from relegation and establishing himself as manager of the Fife club.
The resounding effect of Stein's move from Celtic to Dunfermline was confirmed when he guided the club to the final of Scottish Cup in 1961, defeating his former club 2-0 in a midweek replay, following a goalless draw at Hampden on Saturday 22 April. It was the first time in Dunfermline's history the club had won the trophy.
Success loomed ahead of him, and it is perhaps the least-recognised of all Stein's achievements that should probably rank amongst his greatest. In the 1962-63 season, Dunfermline qualified to play in the Inter-Cities Fairs Cup, and the Pars eliminated Everton 3-1 on aggregate, conceding only one goal at Goodison Park in the first leg. But it was the monumental performance in the next round that sent shockwaves around Europe, when Dunfermline clawed back a four-goal deficit from the first leg of their encounter with Spanish giants Valencia, and notched up an incredible 6-2 scoreline at East End Park to take the match to a play-off in Lisbon.
Shortly after his spell at Dunfermline, Stein was appointed manager of Hibernian, where he won the Summer Cup and expanded his talents as a manager. However, his spell at the Edinburgh club was short-lived, and just one year later, in 1965, he was approached by a crisis-struck Celtic to return to the club as their manager.
Success in Glasgow with Stein at the helm was almost instant, and for the next 13 years, Celtic's dominance of Scottish football became supreme. He started by guiding the team to the Scottish Cup and defeating his former club, Dunfermline; Celtic's first major win since 1958. He went on to win the club's first ever domestic treble and set a phenomenal Scottish football record of nine successive league championship titles in a row from 1966 to 1974. In 1966, Celtic also reached the semi-finals of the European Cup Winner's Cup, where they eliminated by Liverpool on away goals.
On 25 May 1967, at the Estadio Nacional in Lisbon, Portugal, Celtic faced Inter Milan in the final of the European Cup and became the first British and northern European club to win the trophy, overcoming the Italian giants 2-1 to bring the famous trophy to back to British shores for the first time ever.
It was the ultimate achievement in an ongoing success story generated by Stein's presence at the club. The early success of Celtic under Willie Maley was completely overshadowed by Stein's unstoppable progress and innovation. Before him, Celtic were not recognised outside of the UK, and barely noticed outside of Scotland. In the three decades before Stein took over, Celtic had won only three league titles, and had not picked up a single piece of silverware since 1958. As many observers have commented over the years, Jock Stein was Celtic; he made the club what they are today and his legacy remains as relevant in the modern era, as it did 40 years ago.