The history of RSC Anderlecht started with the foundation of the association football club Sporting Club Anderlechtois on 27 May 1908 by a dozen of football lovers gathered by Charles Roos at the Concordia café (located on Rue d'Aumale in the Brussels municipality of Anderlecht).
The early years (1908–1935) Charles Roos was named as the club's first chairman. SC Anderlechtois won their first game 11–8 against Institut Saint-Georges. The ground of the club was then located near a cemetery in the current Rue du serment/Eedstraat, in the Scheut neighbourhood, about 800 metres away from the present stadium. As they were winning most of their matches, club secretary Michel Hames decided to join the official competitions in 1909. They began at the third level of provincial football and at the end of the season, they had already qualified to play in the higher division, finishing third behind the C teams of U Saint-Gilloise and Uccle Sport.
In 1911, Théo Verbeeck, then a forward at the club, became the club's second chairman at the age of 23. In 1913, Anderlecht reached the national level of football, gaining promotion to the Promotion, then the second level of football in Belgium. They ended the following season in fourth place (behind Uccle Sport, RC de Malines and FC Malinois). Because of World War I, the championship was then stopped until 1919. With the popularity of the team increasing, however, it was decided in 1917 that Anderlecht would move to the Astrid Park (known as the Meir park at that time) in a new stadium. They baptized the stadium Stade Emile Versé in honour of the club's first major patron, the industrialist Emile Versé. In 1919–20, Anderlecht finished third, failing to qualify for the top division.
For the following season, Sylva Brébart was appointed at the head of the team, becoming the first manager of the club, and Anderlecht finished together with FC Liégeois in third place once again. However, this time, the Royal Belgian Football Association had decided to let two more clubs play in the first division, which meant that the top three clubs in the Promotion would be promoted. FC Liégeois and SC Anderlechtois thus played a play-off game for promotion at the Daring Stadium in Molenbeek-Saint-Jean, which ended in a 1–1 draw. The replay was played in Tilleur and won by SC Anderlechtois (1–0) with a decisive goal by midfielder Maurice Versé. Ferdinand Adams was also one of the major contributors to this success, as he scored 30 goals in the championship in his second season with the club.
The first season at the top level for Anderlecht was tough as the club finished in 12th position (out of 14). It was striker Henri Thaels who scored the club's first goal ever in the first division, on 4 September 1921 in a game against FC Brugeois. In August 1922, Sylva Brébart was replaced by the Belgium national team's former manager Charles Bunyan, Sr. Ten days after the contract was signed, the new manager died and was replaced by his own son, Cyrille Bunyan. With only 15 points from 26 matches (a win earning two points at the time) at the end of the 1922–23 season, Anderlecht was unable to secure their status in the first division. They won the second division in the following season and finished ninth in the first division in 1924–25, but were relegated again in 1926. In total, they were relegated four times in ten years to the second division (1923, 1926, 1928 and 1931), earning themselves the mockery of local rival clubs Union Saint-Gilloise and Daring de Bruxelles.
Anderlecht achieved their best league position up to that point in 1929–30, when they reached the fifth spot in the top division. Twenty-five years after their formation, in 1933, the club changed their name to Royal Sporting Club Anderlechtois. During the 1934–35 season, the club was trained by Charles Gillis, but the team was composed by manager Claude Leclercq. After a bad start (two wins and four defeats in six matches), Claude Leclercq was sacked and the team was then composed by a committee (including the chairman Théo Verbeeck and the former manager and goalkeeper Florimond Plasch) up to the end of the season. This was a success, with Anderlecht winning one of the two tiers of the second division (the other one was won by RFC Brugeois) and promoting to the first division again, where they have remained since.
First major successes (1935–1968)
Anderlecht reached fifth place in the first division again in 1938–39. The championship was then suspended due to World War II for two seasons. When it resumed in 1941–42, they finished sixth. At the end of this season, Anderlecht signed striker Jef Mermans from K Tubantia FC for 125,000 Belgian francs, a record fee in Belgium at that time. With the help of their striker (38 goals in 34 matches), soon nicknamed "The Bomber", Anderlecht won their first league title in 1946–47 after having finished second in 1943–44 and third in 1945–46 (the championship was cancelled in 1945). Their success increased in the following years as they won six more titles between 1948–49 and 1955–56, winning three consecutive titles twice.
After the 1949–50 season and the club's third league title, Bill Gormlie was appointed as a manager to replace Ernest Churchill Smith. Gormlie would become the longest-serving manager of the club, working at the head of the first team for nine seasons and 294 matches. He would also become the manager with the most championship titles for Anderlecht, with five wins. In the summer of 1952, Anderlecht celebrated the 40th years of Théo Verbeeck as chairman of the club and the club's fourth title, and the municipality changed the name of the stadium's street to Avenue Théo Verbeeck/Théo Verbeecklaan in his honour. A couple of weeks later, however, on 2 August, he died. He was replaced by a former player, Albert Roosens, at the club since 1943 as a joint secretary. Their 1954–55 title earned them the right to represent Belgium in the first ever European competition, the 1955–56 European Cup. Anderlecht lost both legs of their tie against Vörös Lobogo of Hungary. However, they won again the Belgian championship that season, and played once again in the European Cup the following year, losing to Manchester United (12–0 on aggregate) in the preliminary round. In 1958, the club celebrated their 50th anniversary by inviting Barcelona and their three Hungarian star players – Sándor Kocsis, László Kubala and Zoltán Czibor – to play a friendly game on 30 August. The match ended in a 3–3 draw. Anderlecht then won again the championship in 1958–59.
During the next season, Bill Gormlie resigned as manager and was replaced by caretaker manager Arnould De Raeymaeker, before French manager Pierre Sinibaldi took over during the summer break. A new era of the club started at this time, with several new players starting in the first team between 1959 and 1961: goalkeeper Jean-Marie Trappeniers, defenders Laurent Verbiest, Jean Plaskie and Georges Heylens, midfielder Paul Van Himst and striker Wilfried Puis. In 1959–60, on their next venture into European competition, Anderlecht lost both legs of their opening tie to Rangers of Scotland. Anderlecht then had to wait until the 1962–63 season to compete in Europe again, with the 1961–62 title, the first of Sinibaldi, and they won their first European match 1–0 with a goal by Armand "Jef" Jurion in the second leg of their tie with Real Madrid following a 3–3 draw in Spain. For the first time, they advanced to the second round, where they beat CSKA Red Star of Bulgaria before losing to Dundee in the quarter-finals.
In the 1960s, under the coaching of Pierre Sinibaldi, the club won five titles in a row (from 1963–64 until 1967–68), which is still a Belgian record. The 1964–65 title was the club's 11th title, then the Belgian record together with Union Saint-Gilloise. The star player of the team in the 1960s was Paul Van Himst (top scorer in 1965, 1967 and 1969 and Belgian Golden Shoe winner in 1960, 1961, 1965 and 1974). On 30 September 1964, the Belgium national team, coached by Raymond Goethals, fielded 11 Anderlecht players against the Netherlands after RFC Liégeois goalkeeper Guy Delhasse was substituted, to be replaced by Jean Trappeniers. The ten other players on the ground were Georges Heylens, Laurent Verbiest, Jean Plaskie, Jean Cornelis, Pierre Hanon, Armand Jurion, Jacques Stockman, Johan Devrindt, Paul Van Himst and Wilfried Puis. In the 1964–65 European Cup, after a 1–0 win at home, Anderlecht lost 2–1 at Bologna, and both teams had to play a replay (in Barcelona) that finished 0–0. Anderlecht finally qualified on the toss of a coin. In the second round, they were knocked out by Liverpool. The season after, they reached the quarter-finals again, this time meeting Real Madrid. But dubious refereeing in the second leg helped the Spanish to progress in the cup after a 4–3 victory on aggregate (the Belgians had won the first match 1–0).
Since the arrival of Sinibaldi, the team had played in a "Brazilian" 4–2–4 formation, a departure from the W-M tactics (defense in a W-shape and attack in an M-shape; i.e., a kind of 2–3–3–2) used by former coach Bill Gormlie. After three consecutive title wins, Sinibaldi left the club in the summer of 1966 and was replaced by Hungarian Andreas Beres, who coached the team to two league championships in the following two seasons. In those two seasons, Anderlecht suffered consecutive second-round knockouts to Czechoslovak sides in the European Cup (Dukla Prague in 1966–67 and Sparta Prague in 1967–68).
The European successes (1968–1984) Anderlecht reached their first European final in 1970 in the Inter-Cities Fairs Cup, which would become the UEFA Cup two years later. That year, it was decided that, in the case of teams being level on aggregate after two matches, the team that had scored the most goals away would qualify. The new rule saw Anderlecht past Dunfermline and Newcastle United respectively at the second and third stages of the competition (having beaten Icelandic side Valur in the first round). In the semifinals, the Brussels team beat Inter Milan, but after they had won the final's home leg against Arsenal 3–1, they lost 3–0 at Highbury in the second leg. Anderlecht also participated to the next and last Inter-Cities Fairs Cup, due to their second consecutive domestic league fourth place, but they lost in the third round to Vitória de Setúbal of Portugal. They finished the championship in third place in that season.
During the summer of 1971, a new chairmen was appointed at the head of the club. Albert Roosens was replaced by former Anderlecht and Belgium player Constant Vanden Stock. He directly transferred several players, among which included Dutch goalkeeper Jan Ruiter and forward Rob Rensenbrink. Anderlecht won their next domestic title at the end of the season, on the last matchday, with a little help from another Brussels team: Racing White's draw with Club Brugge, who had gone into the final round of matches as league leaders, enabled Anderlecht to claim the championship. They also won the Belgian Cup for the second time, making also their second double.
The next season, Club Brugge won the championship at the Astrid park, a measure of revenge after they had finished second for five seasons in a row, while Les Mauves et Blancs ended the season in sixth place, their worst performance since 1952. This was the beginning of a long rivalry between the two teams. Anderlecht though managed to secure a place in Europe by winning the Cup again, entering for the first time the European Cup Winners' Cup, as their tenth consecutive European season. That year, Anderlecht finished on top once again with a team led by players Rensenbrink, Ludo Coeck, Paul Van Himst and Attila Ladinszky. Before the 1973–75 season, chairman Constant Vanden Stock decided to have the club's first shirt sponsor printed, which was his own brewery Belle-Vue.