Unamuno worked in all major genres: the essay, the novel, poetry and theatre, and, as a modernist contributed greatly to dissolving the boundaries between genres. There is some debate as to whether Unamuno was in fact a member of the Generation of '98 (an ex post facto literary group of Spanish intellectuals and philosophers that was the creation of José Martínez Ruiz — a group that includes Antonio Machado, Azorín, Pío Baroja, Ramón del Valle-Inclán, Ramiro de Maeztu and Ángel Ganivet, among others). His philosophy perhaps foreshadowed the thinking of 20th century existentialists such as Jean-Paul Sartre and Albert Camus.

In addition to his writing, Unamuno played an important role in the intellectual life of Spain. He served as rector of the University of Salamanca for two periods: from 1900 to 1924 and 1930 to 1936, during a time of great social and political upheaval. Unamuno was removed from his post by the government in 1924, to the protest of other Spanish intellectuals. He lived in exile until 1930, first banned to Fuerteventura (Canary Islands), from where he escaped to France. Unamuno returned after the fall of General Primo de Rivera's dictatorship and took up his rectorship again. It is said in Salamanca that the day he returned to the University, Unamuno began his lecture by saying "Yesterday, ...", as Fray Luis de León had done in the same place four centuries before, as though he had not been absent at all. After the fall of Rivera's dictatorship, Spain embarked on its second Republic, a short-lived attempt by the people of Spain to take democratic control of their own country. He was a candidate for the small intellectual party Al Servicio de la República.

The burgeoning Republic was eventually quashed when a military coup headed by General Francisco Franco caused the outbreak of the Spanish Civil War. Having begun his literary career as an internationalist, Unamuno gradually became a convinced Spanish nationalist, feeling that Spain's essential qualities would be destroyed if influenced too much by outside forces. Thus for a brief period he actually welcomed Franco's revolt as necessary to rescue Spain from radical influence. However, the barbarism displayed by the Francoists caused him to oppose both the Republic and Franco. As a result of his opposition to Franco, Unamuno was effectively removed for a second time from his University post. Also, in 1936 Unamuno had a famous brief quarrel with Millán Astray at the University. Some time after that, he was placed under house arrest, where he remained until his death.

Source: Wikipedia.com