José Aguirre was born in Spain in 1904. Aguirre trained as a lawyer before becoming a Basque politician. On the outbreak of the Spanish Civil War he formed the first government of the Republic of Euzkadi. Aguirre pledged support for the Popular Front government in return for local home rule.

The relationship between Aguirre and the Republican government became strained in 1937. Aguirre feared that the government based in Valencia wanted more control over the Basque affairs. At the same time Juan Negrin suspected that the Basque government was trying to negotiate a separate peace with the Nationalists.

The Nationalist Army continued to invade Basque territory and in July 1937 Aguirre was forced to flee from Bilboa. He established a government in exile and remained president of the Basque people until his death in 1960.