He was also one of the founders and president of the Galicianist Party and had a great influence on the renovating group of Galician art known as Os renovadores.

On the day of his birth he was baptised at the parish church of Santa Comba with his maternal aunt and uncle, Pilara and Francisco Castelao, as godparents.

As a caricaturist, Rodríguez Castelao focussed on the everyday in a humorous way, although after experiencing the Spanish Civil War, he turned to using his art to denounce the cruelties of Fascism in a collection of paintings.

Rodríguez Castelao developed an emotional attachment with Pontevedra and frequently claimed he wanted to be considered a native of that city; he even expressed a will to be buried there and not back in his original Rianxo or elsewhere.

In his book Sempre en Galiza[page needed] he states that all his works, talent and efforts would always be used for the profit of the Galician cause.

From New York City he cruised to Buenos Aires, where in 1941 he performed for the first time the play Os vellos non deben de namorarse, Castelao's contribution to Galician theatre.

In 1946 he was appointed as minister without portfolio in the Spanish Republican government in exile led by José Giral, while living in Paris.

[9] In 1947, back in Buenos Aires and after being diagnosed with lung cancer, he published As cruces de pedra na Galiza.

He accepted the autonomy granted to Galicia by the Second Spanish Republic as a tool to construct a possible Galician State, in federation with other Iberian nations.

At the end of his life, and as expressed in the final parts of Sempre en Galiza[page needed], Castelao became somewhat disappointed with the Spanish Republican politicians in exile, and began to discuss the advantages of a completely independent Galician State.

(...) Hespaña, a name we had to sweeten by adding a letter in order to make it respectable to our eyes, since all we can say about its government is that it is hateful because it is even more hypocritical than simply tyrannical.

Then again, Castelao seemed to have gained a sympathy for the idea of full independence for Galicia in the last years of his life, as succinctly mentioned in Sempre in Galiza and in a number of late texts and letters.

We are "secessionist" when we defend the intrinsic values of our nation, and we are "unionist" when we consider that there is a need to co-ordinate our relative values with the relative values of the rest of Hespaña and the World.The fundamental problem of Spain can only be resolved in two ways: federation or secession.From an ideological point of view I am willing to consider secession and all of its consequences, because I am a nationalist (...) (I would support an) open and frontal fight for our national independence, in case no other possibility of federation or confederation with Spain was possibleAlthough bilingual in Galician and Spanish, Castelao always wrote and published in Galician, with very rare exceptions.

In his travels to Portugal, and sporadically to Brazil while residing in Argentina, Castelao was impressed with how easily he could use his native Galician in order to communicate freely with Portuguese speakers.

He did make use of old Galician words, often common in Portuguese, as a way to progressively introduce them into colloquial speech; for example his preference for the term Galiza instead of Galicia for the name of the country.