With political stability, the role of secretary of state has become less prominent, though no less significant.
Serving since 2004 as chair of the leading peace-building charity on the island, I have witnessed remarkable events in Anglo-Irish relations.
As Owen Paterson moves on, it would be remiss not to note his contribution in Ireland; often discreet, his guiding hand was key to ground-breaking moments.
His period in office was not without challenges. An early task was the prime minister's public acknowledgement of the pain caused by Bloody Sunday.
A rising dissident threat impacted with the tragic murder of Constable Ronan Kerr.
With stark lows come tremendous highs and improving relationships culminated in the historic visit of the Queen to Ireland, amplified by her recent meeting of the deputy First Minister Martin McGuinness, hosted by Cooperation Ireland.
Theresa Villiers arrives at Hillsborough Castle with many challenges. This summer, we have witnessed how division manifests itself with contention.
I thank Mr Paterson for his commitment and I am confident his term will be remembered as one of triumph.
Chair, Cooperation Ireland