ELI5: Alfredo di Stefano's transfer to Real Madrid

http://en.wikipedia.org/wiki/Alfredo_Di_St%C3%A9fano the part about the controversy is pretty well summed up here

Di Stéfano's transfer to Spain would prove controversial. Real Madrid first noticed Di Stéfano at a friendly in the Nuevo Estadio Chamartín in 1952 where Di Stéfano's Colombian side, Millonarios, defeated Real 4–2. Then Real Madrid president Santiago Bernabéu Yeste was greatly impressed with Di Stéfano, and in July 1953, Real Madrid reached an agreement with Millonarios for Di Stéfano's transfer to Real Madrid.

However, Real Madrid were not the only La Liga club to notice Di Stéfano during his time at Millonarios. The mission to secure the signing of Di Stéfano to Barcelona had first been given to the Catalan Ramon Trias Fargas, who, besides being a lawyer and expert in commercial law, was the son of one of the share-holders of Millonarios, where Di Stéfano was playing at the time. According to Trias Fargas, FC Barcelona's own management effectively obstructed the transfer when club president Enric Martí Carreto also involved Barcelona chief scout Josep Samitier in the negotiations. Samitier, in his turn, brought in Joan Busquets-Baró, a Catalan acquaintance living in Colombia, to speed up the talks with Millonarios (and according to Finestres & Luque,[16] with Di Stéfano himself). Busquets, a director of Millonarios' rivals Santa Fe, seems to have tried more to sabotage the deal than to secure it. After issuing a harsh ultimatum to Millonarios to accept a modest offer for the player, he organized Di Stéfano's defection from Colombia when the ultimatum was rejected, despite Di Stéfano owing the club money. River Plate, who owned the rights of the player from 1955 onwards, had accepted the transfer on the condition that Millonarios also agreed upon the transfer, but Millonarios was no longer interested in doing so after Busquets' ultimatum and bullying tactics. Trias Fargas' negotiations with the Colombians regarding a transfer sum were also breaking down when Enric Martí, despite assurances to Trias Fargas that he would pay whatever price Trias Fargas thought necessary, rejected a figure whenever it was agreed between the lawyer and the Colombians. Trias Fargas blamed Enric Martí, claiming Barcelona directors had allowed him to spend $20,000 but Carreto only accepted to offer $10,000 plus the player's debts.

In 1953, Di Stéfano signed a deal with Barcelona, and FIFA, who didn't know anything about Di Stéfano having left Millonarios without permission, authorized the transfer from River Plate. The Spanish Federation, however, did not recognize the deal. According to Andres Ramírez, the Spanish Football Federation secretary, both Millonarios (who owned the rights of the player until the end of 1954, according to the agreements reached in the Lima Pact) and River Plate's consent were needed in order for Di Stéfano to sign up with a Spanish club. By this point, Real Madrid had signed their own transfer agreement with Millonarios, and indeed Millonarios reported to FIFA the anomalous situation of the Argentinian, so FIFA itself demanded that the Spanish Federation solve the problem. On 22 May 1953,[17] Di Stéfano arrived in Spain to conclude his contract with Barcelona but during the discussions with the Federation, Real Madrid's president Santiago Bernabéu, acting upon the apparent division within the Barcelona management, convinced him to sign for them instead.

During the parallel negotiations between the two Spanish clubs and Millonarios, the Spanish Federation issued a ban on foreign players in the Spanish league. On 15 September, the Spanish Federation made public the decision, signed by club presidents Martí and Bernabéu, to allow Di Stéfano to play four seasons in Spain – two for FC Barcelona and two for Real Madrid, to be played alternately. The agreement created such a storm of protests by the rest of the Barcelona management and the fans that Martí resigned a week later. The reasons for Barcelona's decision to let the player go to Madrid are disputed by the two clubs. This incident exacerbated the traditional enmity between the two clubs.

Millonarios = River Plate