Giles was spotted in Dublin playing for the famous Nursery Stella Maris Football Club in Drumcondra he began his English career with Leeds’s rivals Manchester United, joining in 1957. He was given an early first-team debut in 1958 after eight of the team died in the Munich air disaster. He was in the Republic of Ireland team before his 19th birthday. He asked for a transfer and joined Leeds for £33,000. He soon showed his worth, as Leeds won the Second Division title in his first season. In 1965 he was in the team which came close to a League championship and FA Cup “double” but which missed out on both, to Manchester United and to Liverpool respectively.
Giles formed a glittering partnership with Billy Bremner as Leeds manager Don Revie built a new team around them. The players had similarities in their styles and were a tremendous foil for one another. Giles was known as the creative force and Bremner as the ball winner, but each was capable of doing the other’s prime job.
In the 1967-68 season Leeds won both the League Cup and the Fairs Cup. That was the first season in which Giles was affected by injury. In 1970 Giles again had a magnificent season as Leeds chased three trophies but lost all three, the League went to Everton on the last day; the FA Cup to Chelsea after a replay; and the European Cup campaign ended at the hands of Celtic in the semi finals.
Leeds won their first FA Cup and Giles his second when they defeated Arsenal 1-0 at Wembley in 1972, yet again they missed out on the League on the final day of the season after defeat to Wolves. Sunderland and AC Milan beat Leeds in the finals of the FA Cup and the European Cup Winners Cup in 1973, rendering Leeds trophyless again. Jack Charlton’s retirement in 1973 also left Giles as the most senior member of the squad. In the same year he started to combine his Leeds duties with a spell as player-manager of his country. In 1974, a 29-match unbeaten run at the start of the season helped Leeds coast to their second title, but then controversy surrounded Giles after Revie quit to take over the England team.Revie recommended to the Leeds board of directors that Giles, nearly 34 and approaching the end of his playing career, should be his successor. The board instead appointed Brian Clough, a brilliant manager but a controversial choice as he had been publicly critical of Leeds in the past and was not an admirer of Revie.
Clough and the players never got on — the players had wanted Giles too — and the board realised their error, dismissing Clough with a big pay-off after just 44 days in charge. Giles still didn’t get the job though (that went to Jimmy Armfield) and concentrated on playing as Leeds chased a place in their first European Cup final. Giles was outstanding in Leeds’ European campaign but was no longer an automatic fixture in the side. After appearing in the 1975 final, which Leeds lost 2-0 to Bayern Munich, Giles accepted an offer from West Bromwich Albion to become their player manager, while still playing for and managing the Irish team. He left Leeds after 12 years, 521 appearances and 114 goals.