He died in Sukarrieta at the age of 38 after falling ill with Addison's disease during time spent in prison. He had been charged with treason for attempting to send a telegram to President Theodore Roosevelt, in which he praised America for helping Cuba gain independence from Spain.
Arana was born in Abando, a neighbourhood that had been recently incorporated into the city of Bilbao as the new extension for the growth of the industrial era. He claimed that he had a quasi-religious revelation on Easter, 1882, that he communicated to his brother Luis Arana. From then he devoted himself to the nationalist cause of Biscay, later extended to the Basque Country.
He was an early defender of the use of the Basque language in all areas of society, to avoid its increasing marginalization in the face of the dominant Spanish. He learnt the language as a young man, but was ready to contest for a professor in Basque position at the Instituto de Bilbao, competing against Miguel de Unamuno and the winner, Resurrección María de Azkue who became an erudite scholar of the language. He made a strong effort to establish a codified orthography and grammar for the Basque language, and proposed several neologisms to replace words of Spanish origin. Some of this innovations like the characters ĺ and ŕ were finally not accepted in the standardization efforts for the Basque language of the 1970s that eventually came with the now standard Basque Batua.
His first published work was Bizkaya por su independencia ("Biscay for its independence"), composed of a mix of historical, pseudo mythical stories and fabrications of earlier battles of the ancient people of Biscay.
In 1894 he founded the first center for the new nationalist party (Partido Nacionalista Vasco), the second oldest party in Spain, to provide a place for gathering and proselitizing.
Sabino Arana, like many Europeans of his time, believed that the essence of a country was defined by its blood or ethnic composition. He was disturbed by the immigration into Biscay of many workers from central and Western Spain during the industrial revolution, into a small territory with little political power, believing that their influence would result in the disappearance of the pure Basque race.
He contrasted the Basque and the maketo (people from the rest of Spain, Maketania)
Another essential part of his ideology was a devout Catholicism; he considered this to be an essential part of the Basque identity. However his Basque nationalism kept him away from Carlism that was the dominant ultra-Catholic and conservative movement in the area and the ideology of his father.
Despite his religious integrism and his extreme xenophobic and racist views, he is considered by many Basques to be the gadfly that sparked the movement for the cultural revival of the Basques, and for the freedom of his people. The PNV, the party in power in the Basque country since the end of Francoism, he created has moved away from his most controversial ideas but not from his figure.
He was a prolific writer, with over 600 journalism articles, most of them with a propaganda purpose. He liked to shock and provoke, in order to get attention from a society that he deemed unaware of its fate. Overall he was in favour of an ethnic cleansing that would eliminate any trace of Spanish blood in order to restore the imaginary pureness of the Basque race.
There are three key aspects of Sabino Arana's political figure:
During his time in prison he proposed the foundation of a "League of pro-Spain Basques", which would have been in favor of Basque autonomy within Spain. It is still unclear whether he had sincerely changed his views or he was trying to improve the conditions of his imprisonment. His death left the question unanswered and neither his brother Luis nor the party followed through with his proposal.
These articles were made in his first ideology as latter he joined several non Basque politicians as Ramon de la Sota, who became a former member of his party.
The Partido Nacionalista Vasco, holders of the intellectual property of his works, has chosen not to reprint them since 1976, keeping only the more "moderate" part of his message in their charter. On the other hand, some Basques still revere him as the father of the nationalist movement, who managed to start the turnaround of the decay of the Basque language and culture. Many Basque cities have streets named after him.
The estate of his Abando home is now Sabin-Etxea ("Sabino-House"), the EAJ-PNV headquarters.
Jon Juaristi has remarked that perhaps the most influential part of his heritage is the neologistic list of Basque versions of names in his Deun-Ixendegi Euzkotarra ("Basque saint-name collection", published in 1910). Instead of the traditional adaptations of Romance names, he proposed others he made up and that in his opinion were truer to the originals and adapted to the Basque phonology. For example, his brother Luis became Koldobika, from Frankish Hlodwig. The traditional Peru, Pello or Piarres ("Peter") became Kepa from Aramaic כיפא (Kepha). He believed that the suffix -[n]e was inherently feminine, and new names like Nekane ("pain"+ne,"Dolores") or Garbine ("clean"+ne, "Immaculate [Conception]") are frequent among Basque females. Even the name of the son-in-law of the king of Spain is Iñaki Urdangarin, Iñaki being an Arana alternative for Ignatius instead of the Basque traditional Inazio.