Robert Grimshaw Dunville acquired Sion House in Johnstown around 1879. Sion House was acquired by the Dunville family as a base for hunting. The Dunville family ran a whiskey distillery and blenders business in Belfast. In 1892 Robert’s son John Dunville married Violet Anne Blanche Lambart, the fifth daughter of Gustavus William Lambart, of Beau Parc, County Meath. John had spent a considerable portion of his time at Sion House as he was growing up. They had four children: Robert Lambart Dunville, John Spencer Dunville, William Gustavus Dunville and Una Dunville. Robert Grimshaw Dunville died in August 1910 and his son, John, succeeded him. John Dunville was Master of the Meath Hounds from 1911 to 1915, succeeding John Watson of Bective House and the Earl of Fingall. John Dunville served for many years in the old Meath Militia, 5th Battalion Leinster Regiment, gaining the rank of Lieutenant Colonel. John Dunville was a keen hunter and a ballooning enthusiast as was his wife.
Their son, Second Lieutenant John Spencer Dunville, died from wounds he received at Epehy in France in 1917. He was protecting an N.C.O. of the Royal Engineers who was cutting wire which had been laid by the enemy. The Victoria Cross was awarded to him posthumously.
John Dunville’s eldest son, Robert Lambart Dunville, who had been educated at Eton, joined the army in 1912 and resigned his commission a year later. At the outbreak of war Robert was commissioned into the Buckinghamshire Yeomanry in October 1914. In April 1915 a Medical Board at the Military Hospital in Cottonera, Malta found that he had just recovered from an attack of acute appendicitis and in view of the probability of a further attack, recommended that he should return to England for an appendicectomy. By September he had fully recovered and in November he transferred as a Lieutenant to the Fifth Reserve Battalion Grenadier Guards. Later he served in the Third Battalion.
He was in Ireland when the rebellion broke out in Dublin in April 1916, and set off to join his regiment. On the way he was captured in Castlebellingham, County Louth by Louth Volunteers who were marching from Dundalk and Ardee towards Dublin.
He later described what happened: Second Lieutenant Robert Dunville, of the Grenadier Guards, said he was travelling by motor car from Belfast to Kingstown on Easter Monday, accompanied by his chauffeur. They arrived at Castlebellingham about ten minutes to seven. When he entered the village he saw three policemen on the left hand side of the road near the railings. He also saw a considerable number of men in motor cars, and some on the road — all armed, some with revolvers, some had automatic pistols, others carbines and ordinary rifles. As he could not get through he pulled his car up, and a man whom he identified as the Denis Leahy, came up and pointed a rifle at him. Then Seán McEntee came up and presented a pistol at him. Robert asked them what it was all about, told him that he wanted to catch the boat from Kingstown, and to let him pass. His chauffeur and himself were placed with the police at the railings. Then a man got out of one of the cars, and aimed a long rifle at him. He heard a report, and somebody at his right hand side shouted, and he found that he himself had been shot; that the bullet passed through his breast from left to right. He saw a rifle still pointed at him after he was hit. After that he fell, and he was removed to his car.
Denis Leahy had pointed his rifle at Lieutenant Dunville and then Seán McEntee gave an order. The rebels got back to their cars, and shots were heard. Lieutenant Dunville was hit, and the charge went through his lung. Almost immediately Constable McGee was hit by four bullets. He fell and died in a couple of hours. Constables Kiernan and Donovan made a run for it and reached the barracks under fire from the rebels. Four of the rebels subsequently stood trial at a court martial on 9th June on a charge of killing a police constable of the RIC at Castlebellingham on Easter Monday, and attempting to kill a military officer. Three men received the death penalty which was commuted to prison sentences; John (Seán) McEntee, Francis Martin, Denis Leahy, while the fourth James Sally was sentenced to penal servitude for ten years.
Robert married in 1918 but divorced in 1921. His life appears to have been difficult and in 1920 he was acquitted of being drunk and assaulting a policeman in London. Much was made of his experience at the hands of the Volunteers at the trial. His collection of animals that he kept in Hollywood, County Down in his private zoo at Redburn House formed the basis of Belfast Zoological Gardens, which opened to the public in 1934.
In 1927 he married for a second time. In 1930 he succeeded his father in the chairmanship of Dunville & Co. Ltd. He never fully recovered from his wounds of 1916 and died suddenly at the age of thirty-eight in 1931. He was the last Dunville family and there was no one with his drive and commitment to succeed him and so the business closed in 1936.