Likiniano fought in the Spanish Civil War, and during the first moments of the military uprising he played a key role in the defence of Donostia, cutting off the coup's advance through Urbieta Street in the centre of the city where the confederal militias' checkpoints were stationed.

Later, when Augusto Pérez Garmendia's column, which had gone out to defend Gasteiz, returned from Eibar, they made the rebels retreat to the Loiola barracks.

During the following months, he took part in the defence of the border between Gipuzkoa and Navarre and, after Donostia fell into the hands of the Nationalists, he continued armed resistance in Aragon and Catalonia.

He later went to France and participated the French resistance to the Nazi occupation, before returning to Euskadi again, where he was involved in the guerrilla activities of the Spanish Maquis.

His vision of unifying anarchism with Basque nationalism, shared with his life-long friend Federico Krutwig, was recognized in the early 1990s by autonomous activists of Bilbao, who created a cultural association that bears his name (Felix Likiniano Kultur Elkartea).