In the appendix of their book, In Spanish Trenches, Barry McLoughlin and Emmet O’Connor list 231 Irish-born participants in the Spanish Civil War that took place from 1936 to 1939.

The highest number came from Dublin and Antrim, with 56 and 47 respectively. There’s then a large gap between the remaining counties, with Cork coming in third at 13.

Counties Meath, Roscommon and Wicklow had zero representatives.

Below is a visualisation showing their respective counties: