The history of cards in football is not a particularly long one when you consider that they were only introduced at the 1970 FIFA World Cup in Mexico. The system was the brainchild of renowned British referee Ken Aston.Born in 1915, Aston worked as an English teacher and qualified as a referee in 1936. Reports suggest that he was also the first referee to wear the black uniform with a white collar that later became mandatory for all match officials(originally, referees wore a white shirt, golf trousers and a sports jacket). Known for his strong character, Aston was keen to change the way in which fair play was evaluated in football. His inimitable style immediately set him apart from other match officials and enabled him to rise through the ranks to ultimately become chair of the FIFA Referees’ Committee.

Referees warned players verbally and dismissed them from the pitch in the event of any further rule infringements. Spectators only realised what was happening when a player began his long despondent or irate walk towards the tunnel. Despite this system, games occasionally descended into chaos.

At the 1962 FIFA World Cup, Ken Aston oversaw the encounter between hosts Chile and Italy, a match deemed risky even before kick-off thanks to the Chilean press’s efforts to whip the country into a frenzy. The match ended with a 2-0 win for the hosts but was later dubbed the “Battle of Santiago” by a British television commentator. Looking back at images from that day, it seems incredible that nobody ended up in the hospital. The fouls were tantamount to assault, fights broke out almost every time players squared up to one another and vengeance was immediately sought for every overzealous tackle. Headbutting, punching and spitting was rampant. Aston ran around frantically in an attempt to separate players and calm tempers, and sent off Italian players Mario David and Giorgio Ferrini, the latter of whom had to be led away by Chilean police after refusing to leave the pitch. In another incident, Chile’s Leonel Sanchez broke Humberto Maschio’s nose with a left hook, but the referee did not spot it and Sanchez stayed on the field. Years later, Aston remarked: “I wasn’t reffing a football match, I was acting as an umpire in military manoeuvres.”In light of this infamous footballing conflict and a number of contentious incidents in other matches, Aston saw the necessity of introducing a clear visual system that could be easily understood by players and spectators alike.
Following an incident in the England vs Argentina match in the 1966 World Cup, it came to Aston's knowledge that Jack Charlton had been booked by the German referee, Rudolf Kreitlein. Charlton called the press office, where Aston was ensconced (as Head of World Cup Referees), in order to confirm the information that he had read within the newspaper that Kreitlein had booked him. Aston, driving from Wembley Stadium to Lancaster Gate that same evening, had Charlton's confusion in mind during the journey.On the trip, as he stopped at a traffic light junction at Kensington High Street, Aston realized that a colour-coding scheme based on the same AMBER/YELLOW ('stop if safe to do so') - RED (Stop) principle as used on traffic lights would traverse language barriers and clarify to players and spectators that they had been cautioned or sent off.Aston later explained that upon arriving at his home, he explained the dilemma to his wife, Hilda. She disappeared into the other room, only to return a few minutes later with two "cards" made of construction paper. She had cut them to fit into his shirt pocket. Thus was devised the system whereby referees show a yellow card for a caution and a red card for an expulsion, Aston presented his idea to the FIFA Referees Committee, who approved the cards’ introduction at the 1970 FIFA World Cup World Cup in Mexico. There, the Soviet Union’s Evgeni Lovchev became the first footballer ever to be shown a yellow card, in the opening match against the host country but the fact that no red cards were brandished during the tournament suggests the new system had a positive effect. The first World Cup dismissal came in West Germany four years later, when Chile’s Carlos Caszely was sent off for committing two yellow-card offences also in a match against the host country.