Harry Owens has researched the history of Spain for many decades and helped organise a 30th Year Commemoration in Dublin in 1966.

Harry co-wrote the book, Brigadista, with Bob Doyle, a Dublin Republican, who volunteered to fight in Spain from 1937 until his capture during the Civil War (1936-39).

Harry outlined the chronology of the war which drew in many fighters from around the globe. Hundreds of Irishmen volunteered to participate on both sides, some of whom had fought in the Irish Civil war, a decade or so  earlier.