Recent politics have revealed a common lack of knowledge about Ireland and Northern Ireland in the Britain at a time when it is of vital strategic importance. What is behind the blind spot? We call this phenomenon ‘The Knowledge Gap’, and investigate how it came to be by comparing the history courses taught in Ireland and the UK, with some striking results. We also hear from experts on Northern Ireland who found themselves in the eye of the storm following the recent election which brought the Democratic Unionist Party unexpectedly close to power in Westminster and unleashed huge demand for crash courses on Northern Ireland. This episode reveals that uncertainty about where the UK begins and ends is widespread — including among those whose job is to know.