For the majority of his playing career he was as a striker for Borussia Mönchengladbach in its golden era of the 1960s and '70s, when they won many national championships and the DFB-Pokal, as well as the UEFA Cup.

[5] In 1965, the club, managed by Hennes Weisweiler, achieved promotion to the Bundesliga,[5][7] with the teenaged striker scoring 23 goals in 25 matches in his debut season.

[11] In 1973, after eliminating Dutch club Twente 5–1 on aggregate in the semi-finals, Borussia Mönchengladbach became the first German side to reach the final of the UEFA Cup.

[7] Borussia lost the away leg of the final against Liverpool 3–0 at Anfield, after the match initially had to be abandoned after 27 minutes due to a waterlogged pitch.

[19] Heynckes was a member of the West Germany team that won the 1972 UEFA European Championship, playing 90 minutes in the 3–0 win over the Soviet Union in the final.

Despite his excellent form at club level, however, he spent most of the tournament on the bench as Gerd Müller, the national team's all-time top goalscorer, was used as the starting centre forward by coach Helmut Schön.

[20] Heynckes was in the starting line-up for West Germany's opening two fixtures against Chile and Australia[21] but then played no further part due to injury and die Nationalelf won their second World Cup, beating the Netherlands 2–1 in the final at Munich's Olympiastadion.

"[22] After his playing career, Heynckes stayed with Borussia Mönchengladbach and served the club for eight more years, first as an assistant and then as a manager, succeeding Udo Lattek in this position in 1979 at age 34.

[27] During the 1980–81 season, Mönchengladbach defeated OSV Hannover, TuS Langerwehe, Bünder SV, and Atlas Delmenhorst to get to the quarter-final of the DFB-Pokal where they lost to 1.

[44] During the season, Bayern went on to lose out on the league title by four points to Werder Bremen[45] and were eliminated in the quarter-finals of the DFB-Pokal[46] and the European Cup.

[68] Heynckes' spell at the Eintracht was problematic and he clashed with the club's star players Tony Yeboah, Jay-Jay Okocha and Maurizio Gaudino.

[75] The following season the club finished ninth in La Liga[76] and reached the semi-finals of the UEFA Cup, where they were beaten by eventual winners Schalke 04.

[77] In the Copa del Rey, Tenerife had a bye until the fourth round, where they were eliminated by Real Betis after losing both legs of the tie.

[80] There, he celebrated one of his greatest triumphs, as Madrid beat Juventus 1–0 in the UEFA Champions League Final for their first European Cup victory since 1966.

[81][82] However, the lack of domestic success – finishing fourth, eleven points behind champions Barcelona – saw his tenure terminated at the end of the season.

[82] Benfica finished third[85] in Heynckes' only full season in charge and were knocked out of the UEFA Cup at the third round with an 8–1 aggregate defeat by Celta Vigo, losing the first leg 7–0.

[87][88] After releasing club icon and captain João Pinto, who then joined Lisbon rivals Sporting CP,[89] after transfer listing him.

[60] In the 2001–02 season, Athletic finished tenth in La Liga,[92] missing out on qualification to the UEFA Cup by a point, and reached the semi-finals of the Copa del Rey.

[106] Heynckes' comeback started well, with Gladbach in fifth position in the Bundesliga at the end of the seventh matchday after winning each of their opening four home matches.

[110] On departing Borussia, Heynckes refused a pay-off and returned his company car to the club office freshly cleaned and with a full tank of petrol.

[131] Despite his success, Heynckes decided not to extend his contract and left Bayer Leverkusen in the 2011 close season to take over at Bayern Munich for a third time.

[138] Bayern started the league season with a surprise 1–0 defeat to Heynckes' former club Borussia Mönchengladbach at the Allianz Arena,[139] before six consecutive Bundesliga wins without conceding took them to the top of the table.

[142] Bayern briefly regained top spot in January and February, but after the Bavarians' draw with Hamburger SV on matchday 20, Dortmund again gained first position[143] and went on to retain their title by eight points, ending the season on a 28-match unbeaten run.

[147] Despite their disappointments in domestic competitions, Heynckes' Bayern had qualified for the 2012 Champions League Final in April 2012, defeating Real Madrid on penalty kicks in the semi-finals.

[154] Bayern's Bundesliga campaign began with a record-breaking eight consecutive wins before they suffered their only league defeat of the season at Bayer Leverkusen.

[155] General manager Uli Hoeneß later stated that it was not Heynckes' decision to leave Bayern at the end of the season and was forced by the club's wish to appoint Guardiola.

[156] Though the club's press release announcing Bayern's agreement with Guardiola had claimed Heynckes would be retiring on the expiration of his contract,[157] he stated he would not make a decision on his future until the end of the season.

[158] After returning from the winter break, Bayern only dropped two points in the entire second half of the Bundesliga season, winning 14 consecutive matches from January onwards and being confirmed as champions on 6 April 2013.

[17][163] In the Champions League, Bayern faced Barcelona at the semi-final stage, thrashing the favourites 7–0 on aggregate to reach a second successive final.

[165] In the 2013 Champions League final, Heynckes' Bayern defeated Bundesliga rivals Borussia Dortmund 2–1 at Wembley, making him the fourth manager (after Ernst Happel, Ottmar Hitzfeld, and José Mourinho) to win the competition with two clubs.