How did the execution haunt young Erskine for life?

Erskine Childer's presidency is something of a tragic tale which begins with his revolutionary father who was executed in 1922, while his then 16 year old son was taken out of his British boarding school to say goodbye.

But why did Childer's father's dark secrets haunt him?

And how did his wife nearly become his successor?

In this episode of Think You Know...The Presidents, Lise Hand and Flor MacCarthy, jump on board what was Ireland's first presidential bus called the 'Wanderly Wagon' to find out what shaped Childers' presidency.