The Betrayal of Christ was painted by Michelangelo Merisi de Caravaggio (1571-1610).

The painting, which is now on permanent loan to the National Gallery of Ireland, went missing in the late 18th century. A Scotsman, William Hamilton Nisbet, bought it in Italy in 1802, thinking it was a copy by the Dutch artist Gerard von Honthorst.

Its true identity was not recognised until the 1990s in Dublin. While examining a number of paintings for the purposes of restoration at the house of the Jesuits in Leeson Street, Sergio Benedetti, senior conservator of the National Gallery of Ireland, was intrigued by the painting depicting the arrest of Jesus as Judas betrayed Him with a kiss. Benedetti identified it as Caravaggio’s long-lost painting.

After the break-up of the Nisbet collection, the painting was purchased in Scotland by an Irish paediatrician, Marie Lea-Wilson. She donated it to the Jesuits in 1934 in gratitude for their support following the shooting of her husband, Capt Percival Lea-Wilson, who was killed by The Squad on the orders of Michael Collins in Gorey, Co Wexford, on June 15, 1920.

At the time Wilson was a district inspector of the Royal Irish Constabulary. He had been a constable in Charleville, Co Cork, before joining the British army in 1915. He had served for a time in France and was in charge of British troops at the Rotunda Gardens when republican prisoners were held there following the Easter rebellion.

He became notorious for mistreating the elderly Tom Clarke and Seán MacDermott. Later it was suggested Collins had him killed in revenge for his behaviour outside the Rotunda.

“Tom Keogh, Pat McCrae, Tom Cullen and other Wicklow men were picked to carry out his execution,” according to Paddy O’Daly, one of the leaders of The Squad. “Men who knew the country were sent because they would have to take to the hills.”

Wilson was shot five times as he was walking home with the daily newspaper between nine and ten o’clock in the morning. From the shots heard and bloodstains found, it would seem he was felled initially by two shots but got up and ran for about 15 yards. There were bullet marks on the wall at the side of the footpath. When he went down again, he was shot repeatedly on the ground and died at the scene.

Dressed in civilian clothes, he had been to the RIC barracks in Gorey and was walking to his home, about a quarter of a mile outside the town. He stopped at the rail station to purchase the daily paper. He had been walking with Constable Alexander O’Donnell, but they parted about 200 yards from the scene of the shooting.

Wilson was reading the newspaper as he walked, so he may not have seen his assailants until the final moments.

Minutes earlier a grocer’s assistant on his way to work had noticed a car in the area. The bonnet was up and four men he did not recognise were standing around the engine, while another man was in the car. After the shooting the car was seen heading in the Ballycarnew direction.

Joe Sweeney happened to be in the bar of the Wicklow Hotel that evening when Collins stomped in. “We got the bugger, Joe.”

“What are you taking about?”

“Do you remember that first night outside the Rotunda – Lea Wilson?”

“I’ll never forget it,” Sweeney replied.

“Well,” said Collins, “we got him today in Gorey.”

If Collins had another reason for killing Lea Wilson, he might not have been able to tell Sweeney without compromising his source, but his remarks would seem to suggest the killing was in revenge for what happened outside the Rotunda on that evening in 1916.

Paddy O’Daly disagreed with this conclusion. “Captain Lea Wilson was not shot because he had ill-treated Seán McDermott and other prisoners in 1916 because there were other British officers just as bad as he had been and no attempt was made to shoot them,” O’Daly argued.

“I believe he was shot because of the position he held at the time, and for no other reason. I am satisfied from my long experience with The Squad that no man was shot merely for revenge and that any execution sanctioned by Michael Collins was perfectly justified.”

There had, however, been no rebel activity around Gorey. Nobody has ever suggested any other specific reason for the killing.

“The town has been one of the quietest, if not the quietest, in all Ireland,” the Irish Times noted the day after the killing. “Up to the present nothing has occurred.”

O’Daly recalled that he was once reprimanded by Collins, who heard he was planning to take revenge on an officer who had shoved his lame daughter to the ground in 1916. O’Daly has been wounded in the Easter Rebellion. While he was in hospital a British army officer came to inform his wife and took a look around her house. As the officer was leaving, a neighbour, Supt John Winters of the Dublin Metropolitan Police, rushed up to him to say there was a large store of guns in the house. Citing his authority as a police officer, Winters began to search the place.

“This is martial law,” the army officer said. “We are in command and you must get out.”

WHEN Winters did not comply, the officer called on two soldiers to put him out. As he was being escorted out, O’Daly’s four-year old daughter called Winters “a traitor” and he pushed her to the ground.

Following the formation of The Squad, Collins was told O’Daly was planning to kill Winters, who still lived near him. “What is this I hear about you going to shoot Winters?” Collins asked him.

O’Daly tried to dismiss the whole thing as a joke. “That is too serious to be a joke,” the Big Fellow insisted.

“The thought of killing Winters had never entered my head,” O’Daly said. “Collins gave me a lecture on revenge and told me that the man who had revenge in his heart was not fit to be a Volunteer.”

Whatever about Collins’s motivation for the killing of Lea Wilson, O’Daly certainly did not heed the Big Fellow’s advice because he later became involved in one of the most spiteful incidents of vengeance in Irish history – the Ballyseedy massacre near Tralee during the civil war in March 1923.

O’Daly was in charge of the Free State troops in Kerry when the nine Republican prisoners were taken from Tralee and deliberately blown up at Ballyseedy.

While the evidence is not conclusive about whether O’Daly actually ordered the killings, he was the commanding officer and he unquestionably covered up for the culprits and made no effort to reprimand them. In a way the Caravaggio painting of The Betrayal of Christ became steeped in Irish history.