Ka cika wannan jumla: An haife shi a Erandio, Biscay, Rubial ya yi aiki da ƙarfe. Ya shiga kungiyar Unión General de Trabajadores (UGT) a shekarar 1920 da kuma Jam'iyyar Socialist Workers ta Spain (PSOE) a shekarar 1922. A shekara ta 1934, an kama shi saboda ayyukan juyin juya hali a lokacin
Asturan ma'aikatan ma'adinai na 1934, wanda aka tsare shi har tsawon watanni bakwai a kan jirgin fursunoni. Daga nan aka yanke masa hukuncin shekaru bakwai a gidan yari saboda tayar da zaune tsaye, amma an ba shi afuwa bayan nasarar Popular Front a babban zaben Spain na 1936.