He was born in Alcalá de Henares in 1980, the second of four brothers in a well-to-do family. He was the son of Esteban Azaña, agricultural owner and mayor of the city, and Josefina Díaz.
He studied law and at that time published his first writings.
In October 1898 he settled in Madrid as an intern at the law firm of Luis Díaz Cobeña, where he coincided with Niceto Alcalá-Zamora, at the same time that he was studying for his doctorate, which allowed him to meet Francisco Giner de los Ríos.
In 1900 he read his doctoral thesis on La responsabilidad de las multitudes, which made him a Doctor of Law.
He frequented the Academy of Jurisprudence, where he gave a lecture on January 22, 1902.
He collaborated in magazines such as Gente Vieja or La avispa, and for a time, he dedicated himself to the family business.
In June 1910 he obtained, by competitive examination, the position of Third Assistant of the General Directorate of Registries and Notaries of the Ministry of Grace and Justice, where he would develop his entire career as a civil servant.
In February 1911, he gave a lecture on "The Spanish Problem", ratifying his democratic convictions for the reconstruction of the State from local life.
He obtained a pension from the Junta para Ampliación de Estudios in order to study law at the École Nationale de Chartes in Paris, where he remained until the end of 1912. From the French capital he would send chronicles to the Madrid newspaper La Correspondencia de España under the pseudonym of Martín Piñol.
He joined the League of Spanish Political Education, led by Ortega y Gasset, and the political project of the Reformist Party, headed by Melquiades Álvarez.
He would then begin his exciting political life that would culminate with important positions as Minister of War and President of the Council of Ministers from 1931 to 1933, and President of the Spanish Republic from 1936 to 1939.
