In Green and Red – The Lives of Frank Ryan by Adrian Hoar
At the onset of the Spanish Civil War, Ryan led the first contingent of Irish volunteers to support the Popular Front against Franco’s Government. He continued to fight in Spain but was captured in April 1938. He was sentenced to death but after representations from Eamon de Valera his sentence was commuted to 30 years.
In 1940 he was sent to Nazi Germany and was as an unofficial ambassador for the IRA working for German intelligence. He died in Dresden in 1944.