She remained politically active all her life and was a personal friend of the Irish republican Michael Collins. Rumours still abound that Littlewood's hand was all over The Quare Fellow and led to the saying "Dylan Thomas wrote Under Milk Wood Brendan Behan wrote under Littlewood". " "One day with Groucho Marx.
Subsequently released from prison as part of a general amnesty given by the Fianna Fáil government in 1946 Behan moved between homes in Dublin Kerry and Connemara and also resided in Paris for a period. He married Beatrice Ffrench-Salkeld in 1955. He was also an Irish republican and a volunteer in the Irish Republican Army.