What happened at Celtic Park on this day in 1965?
The Hoops legend arrived as Celtic manager having previously worked with Dunfermline, Hibernian and Scotland and went on to enjoy 13 trophy laden years with the Glasgow club, remaining by far the most decorated Bhoys manager in the history of the club.
On the day he signed, Stein became the club's first ever protestant manager and only the fourth ever boss in their history. He took over at a time when the Bhoys were a struggling side, but quickly put things right by achieving a 6-0 victory in his first competitive match in charge.
In his first season, Stein managed to capture the Scottish League, triggering a run of nine league championships in a row, the first of any Scottish team to achieve this. The manager added a 10th and final league title in 1977, before moving on to Leeds United in 1978.
However, Stein's greatest ever achievement came in 1967, when he managed an entirely Scottish XI, all born within 10 miles of Celtic Park, to the European Cup, beating Inter Milan 2-1 in the final in Lisbon to become the first ever British club to win the competition.
His achievement will forever be etched in British footballing history and remains Celtic's finest footballing accolade, setting them apart in an elite and exclusive category of football teams to have won the prestigious competition.
The Scotsman famously explained to his players prior to the 1966/1967 season that he believed the team could win everything and sure enough, as predicted, his side went on to secure an emphatic quintuple of the European Cup, Scottish League Championship, Scottish Cup, League Cup and Glasgow Cup.
On this day in 1965, Celtic fans could not have imagined what was about to take place at their club across the next decade.