Historians of the Easter Rising have often puzzled as to why the rebels did not attack Trinity College, Dublin.

The college had strategic significance in the middle of Dublin city but was also a symbol of British cultural life in Ireland.

New Zealand historian Dr Rory Sweetman said the notion that the rebels left Trinity alone is one of the “historical orthodoxies” of the Easter Rising and is wrong.

He argues the rebels did attack Trinity College, but were repulsed by colonial troops including five from his native country.

Dr Sweetman from the Trinity Research Centre for Contemporary Irish History has used sources from the Bureau of Military History and letters from four of the five New Zealanders involved to prove there was an attack on Trinity.

The attack took place at midnight on Easter Monday at the end of the first day of the battle.

Dr Sweetman’s main evidence to bolster his argument is a witness statement from Frank Thornton of the Irish Citizen Army.

He was told by James Connolly to occupy buildings in Fleet Street overlooking Trinity to provide a covering party for men from the GPO garrison who intended to capture the university.

Thornton and his men occupied the Pearl Bar and climbed on to the roof where they proceeded to fire on the college.

In his statement to the Bureau of Military History, Thornton remembered: “From the dispatch I understood that we were to act as a covering party on both sides of the road to enable a force from the GPO to attempt to capture Trinity College.

“This job was abandoned and on Easter Tuesday morning I was instructed to evacuate the position and return to the Post Office.”

His testimony would appear to be corroborated by statements from some of the New Zealand troops involved who were part of an Anzac contingent on furlough in Dublin.

Bugler JC Garland from Auckland said they had reported to Trinity at 3pm on Easter Monday. Having fortified the college, they went to sleep.

“At 11pm, they woke us up and took the colonials up to the roof, where we were to snipe. We remained on that roof from midnight Easter Monday till midnight on Thursday without a wink of sleep – exactly 72 hours.”

Another compelling account was left by Alexander Don from Dunedin. He was off duty when the Rising began. On passing Trinity College, he was ushered in by a porter and asked to defend the campus.

In his letters home, he stated that they prevented the rebels from taking the Bank of Ireland opposite the college, but Dr Sweetman contends that it is clear from Thornton’s account that the rebels were trying to take the university instead.

Don wrote: “There were only about 30 armed men in Trinity that night, and as it occupies a whole block it took some holding and we were right in the centre of the rebels”.

Dr Sweetman said he intends his paper, to be presented on Wednesday, to present a “radically different twist to a story that most Irish people believe they already know”.

He also suggested that had the rebels captured Trinity, the history of the university might have been different. The British would likely have reduced to rubble as they had done the GPO during Easter Week.

In that case, he believes, Trinity would not have been rebuilt after independence because of its status as the seat of British intellectual life in Ireland.