If you've never heard of Helios Gomez, neither had I.
Even the present-day Spanish authorities aren't too comfortable with his memory, and have partly or wholly destroyed the beautiful Capilla Gitana, - Gypsy Chapel - which he created by painting frescoes on the walls of his cell when he was imprisoned in the Modelo prison in Barcelona in 1945-6 and 1948-5). I have only found two images of this once much-loved work of art, the most remarkable of which is this uniquely fresh and vivid painting of Madonna and Child.
Helios was a revolutionary who fought against Franco both as a soldier and as an artist. Most of the pictures by which posterity will know him were published as anti-fascist propaganda, but his true legacy is lovingly remembered by the Associació Cultural Helios Gómez.
I only heard of Helios through an interview with Damian Le Bas by Clare-Marie Grigg, editor of Impirica. Damian himself is editor of Travellers' Times as well as being a poet. I hope he won't mind my saying that you couldn't find a better introduction to him than Clare-Marie's interview and his own poem and video, Belong.