Charles is a great-grandson of the 7th Marquess and Marchioness of Londonderry.
"WE all were visiting Mount Stewart together, which was a plan we jointly made a couple of weeks previously.
We walked around the Lake, up to Tir Nan Og which had been left unlocked in order for me to see the recently installed Headstone on my mother's grave for the first time (following her burial at Mount Stewart in 2015).
Then we went up to the Farm because Jonathan wished to see all of the eighteenth century farm buildings which are unchanged since the time of the famous statesman Lord Castlereagh growing up at Mount Stewart.
The farm buildings are currently being re-roofed by the National Trust, after the NT bought the Farm last year from my late grandmother's Trustees.
The oak trees in the demesne which are known to have been planted by Castlereagh himself.
After seeing the Farm, we then walked up to the Temple of the Winds, which neither Jonathan nor Theresa had visited before, and enjoyed the views from the Temple across Strangford Lough towards Scrabo Tower and the site of the swimming pool marked by its lone palm tree.
The two photographs were taken by Theresa's bodyguard from the Close Protection Unit, and afterwards we all lunched at the National Trust's Bay Restaurant.
Theresa and I are cousins because we are each descended from two brothers of the 4th Earl of Clarendon, namely the Hon Thomas Villiers MP (me) and the Hon Edward Villiers (Theresa).
Some people may think the Villiers family is wholly English, though in fact it has long standing Irish connections dating back to Theresa's and my direct ancestor, Sir Edward Villiers MP (1585-1626), who was appointed Lord President of Munster; and who lived, died, and was buried in Youghal, County Cork."