Owner of iron mines, where he based his empire, he exploited them and carried out the entire process until their conversion into consumer goods by his own means.
Even though iron mining was the basis of his industries, he did not hesitate to participate and invest in the new sectors that were beginning to develop in the country, such as metallurgy, banking, chemistry, transportation, telecommunications, and press.
[1] He founded the Ibérica Telecommunications Company, the basis of the current Telefónica, and was the owner of not only land and means of transportation, but also of the Bilbao newspaper El Nervión.
[1] Juan Tomás Gandarias was born in the Biscayan town of Portugalete in the Basque Country on 8 March 1870, as the first-born son of Pedro Pascual Gandarias (1848–1901), an industrialist and businessman who had participated in and promoted the industrialization of Biscay, and of Victoria Durañona y Santa Coloma,[3] daughter of Juan Durañona, from a family of wealthy iron mining owners.
[1][2] On the same day of the wedding of his parents, Juan Durañona established the creation of the Durañona y Gandarias company, the embryo of a great industrial and mining emporium that was inherited by their first child, Juan Tomás, who also had a marriage of convenience (the so-called policy of links), as he wed Cecilia Urquijo y Ussía, daughter of the Marquess of Urquijo, on 17 May 1900.
For instance, his sister Casilda married José Joaquín Ampuero, belonging to a Durango family related to the Bank of Bilbao [es] and numerous companies.
[4] Gandarias obtained a degree and doctorate in Civil and Canon Law from the Universidad Central de Madrid and completed his training with financial and industrial studies.
[4] The power of Gandarias' wealth comes obviously from the inheritance he received from his father, but that was only the first step because over the years he demonstrated, with his business, investment, and modernized union, the possibilities that he offered.
[4] Upon the death of his father in 1901, Gandarias took charge of the family businesses, and in the following year, in Bilbao, he participated in the founding of Altos Hornos de Vizcaya, a Spanish metallurgy manufacturing company, which would ultimately be the pillar and the key piece on which he supported all of his businesses and empire, becoming the largest company in Spain for much of the 20th century, employing 40,000 workers at its height.
[1][4] The main company was Altos Hornos de Vizcaya, but he also participated in Duro Felguera, La Basauri, and in three Spanish Societies of metallurgy: Metallic Constructions (which would later give way to CAF), Evaporation, and Rational Combustion.
[6] With the help of his brother-in-law and trusted man José Manuel de Arispe, the Marquis of Urquijo, he appeared on the boards of the Banca López Bru and of the Banco Central [es].
He also participated in Patentes Flamma Carbo S.A., La Papelera Española S.A. [es], and the Spanish Coal Distillation Company.
[4] He presided over companies such as La Basconia S.A. and Talleres de Deusto, where Gandarias invested in their development, both technological and social.
[1][4] The numerous companies that made up the company were directed by him or by men he trusted, most notably his uncle, José Manuel de Arispe, founder of the Banco de Comercio and director of Banco Bilbao, and Francisco Pérez-Pons, a professor of General and Business Accounting at the School of Higher Commercial Studies of Bilbao.
[2] This League was a political union that brought together all liberal monarchists, Maurists, conservatives, and independents from Biscay, such as Biscayan industrialists.
[1][4] During the dictatorship of Primo de Rivera, he withdrew from politics as well as during the Second Spanish Republic, except for the specific management he carried out with Indalecio Prieto, with whom he maintained a friendship, to alleviate through public works and subsidies the industrial and employment crisis that took place between 1931 and 1933 in Biscay.
[2] On one occasion, at the beginning of August 1920, he won a regatta in Santander, as the owner of Alai against Giralda V, owned and skippered by Alfonso XIII.