My father was a volunteer in Spain, where he was wounded and imprisoned until the end of the war.
He came back with a number of songs including 'Viva la Quince Brigada' which, to my eternal shame, I took no great interest in when I was younger, and so never learned or recorded.
I do remember him singing them around and even 'osmosised' some of them, though, as I have no Spanish, the memories are phonetic.
I am pretty sure 'Viva' was pretty much as Joe gives it, with the addition of a couple of verses I never managed to pick up; one containing a reference to 'reckatays' (hand grenades) (that's how it sounded to me), and another he would never explain as he said "it contained words I should never use" - he was rather strict on that sort of thing.
I would appreciate help with a couple of other songs he had.
One started (again phonetic);

En el Monte de Narranco aye,
Una quente ce mana
Sangre de los Asturiano,
Que muereron en battalia.

Trans;
In the Mountains of Narranco
There is a fountain
That gives forth blood of the Asturians
Who died in battle there.

If you want to write to me,
And you don't know where I am,
In San Perdro De Cadenya (Saint Peter of the Chains),
Without tobacco or money.

Another he called 'An Englishman came to Bilbao' I can only remember the tune for.
Apologies to all for the efforts at spelling.

My father had a pretty hard time in San Sebastian prison in Spain and it was often difficult to get him to talk about it.
He was traumatized by having to witness the execution of dozens of young men, little more than children, who had been arrested in a village in the area. The local priest insisted on their execution because he was afraid he would be identified as a collaborator if the war went the wrong way for him.
When he returned from Spain my father found himself with a MI5 record as 'a premature anti-fascist', which he was extremely proud of, though it did get him blacklisted from work.
The only employment he could get was away from home with Wimpey and MacAlpine, so my sister and I hardly knew him till I was 14, when he finally came home.
I have a recording of a radio programme somewhere on the songs of the Spanish Civil War, made by Jim Lloyd and based on the experiences of Joe Cooney, a friend of The Ian Campbell Folk Group, which I will try and dig out, if anybody is interested.
Jim Carroll