It is a historical comedy about the conflict between Edward III of England and his wife Philippa of Hainault over his plans to punish the leading citizens of Calais for resisting the 1346 siege.

[1] Rodin himself had once said of Shaw that his obsession with "cold" reason was "modified to vapour by his temperamental shyness and his Irish sense of humor".

King Edward III of England intends to hang six leading citizens of Calais for resisting his siege of the town, but he must keep his plans from his wife Philippa, whose forgiving nature is such that she will plead for their lives.

Philippa finds out about Edward's plan and uses all her wiles to persuade him to change his mind, clinching her case by saying that the brutality could adversely affect their unborn child.

In the preface Shaw justified the apparently lightweight character of the piece, by arguing that the purpose of a play is to create elegant order from chaotic experience.