In the divided nation of Ireland, rugby union seems to offer a unique form of unity, with one national team representing two countries. This week's 'Rugby Reloaded' talks to Dr Liam O'Callaghan about the roots of Irish rugby and the reality behind its apparent national unity between North and South, and Catholics and Protestants.

For more on the history of rugby and the other football codes, take a look at www.rugbyreloaded.com (which also has show notes and links for this episode) and follow me on Twitter at @collinstony.