Researching Mario Conde

Son of a humble customs inspector, he was noted for his studying and hard-working capabilities, which led him to obtain the highest distinction of his year's Law promotion at the University of Deusto. Conde's career came to the spotlight when, age 24, he became the youngest State Lawyer in the history of Spain, achieving also the highest grade ever attained in the corps. He remarkably earned the title in little more than a year, when the average candidate took 5.

After working for two years in the Ministry of Finance, Conde met Juan Abelló who, convinced of his talent, offered him a place as board member at his family's laboratory. Following the sale of the laboratories to Merck Sharp & Dohme in 1984, they gained control of Antibióticos S.A., an important antibiotics firm at the time. In March 1987, Conde and Abelló took part in what became the most ambitious transaction in the history of private business in Spain, the sale of the 100% of shares of Antibióticos S.A. to Montedison for US$450 million (approximately US$1 billion today).

The exceptionally wealthy Conde and his partner Abelló, who had amassed a fortune following the deal with Montedison, bought a significant amount of shares of Banesto, one of the largest banks in Spain, so to become members of the management board. This motivation, initially held by Abelló himself, eventually led to a role reversal and Conde was appointed executive chairman on 30 November, becoming the youngest financial chairman of the moment. As a result of an allegedly corrupt management of the bank and excessive credit-lending, there was a patrimonial hole in Banesto tentatively estimated at €3.6 billion (equivalent to roughly US$7.2 billion today) on 28 December 1993. Luis Carlos Croissier, the President of the Comisión Nacional del Mercado de Valores, the financial regulator of the national securities markets, decided to impose a trading halt on Banesto, and Luis Ángel Rojo, the Governor of the Bank of Spain, communicated the intervention of the banking entity, tasking Alfredo Sáenz Abad with chairing the board of directors of Banesto in a temporary basis. Conde, who stayed in preventive detention from December 1994 to January 1995, faced a trail of judicial problems. He was sentenced to 10 years in prison in March 2000 by the Audiencia Nacional (raised to 20 years in 2002 by the Supreme Court). He in fact served 11 years before being paroled.

Mario Conde was seen for many years as the ultimate societal role-model. His embodiment of the self-made man was admired by many, dubbing him "the real life Great Gatsby" but also "Spain's Machiavelli". Kroll Associates described him as “a manipulator, voracious womaniser, and a prominent Mason who dabbled in the occult; Suave and immaculately elegant".