British actor Judi Dench has become a patron of a former Irish regiment in honour of her father who served in the first World War.

Reginald Dench was born in England in 1897 but grew up in Dublin. When war broke out he signed up with the 7th battalion of the Leinster Regiment at the age of 18.

He was commissioned as a second lieutenant, the lowest rank of commissioned officer in the British army.

He incurred an injury while training in Trinity College Dublin in 1916 and missed the Battle of the Somme, where the 7th battalion suffered heavy casualties at Guillemont and Ginchy.

He had an eventful war, however, and twice won the Military Cross – the second-highest award for gallantry given to commissioned officers at the time.

The first, in March 1917, was for repelling a trench raid at Ypres. The second was won after he led a dangerous reconnaissance on a German trench at Arras in October 1917, which cleared the way for a larger attack.

He was home on leave six days before the German Spring Offensive of March 1918 in which every single officer in his battalion was either killed, wounded or captured.

After the war he returned to Ireland to study medicine, where he met Dublin woman Eleanor Olive Jones. They married in 1924.

There was a surplus of doctors in Ireland at the time of Irish independence so he moved to York to work as a GP. Judi Dench was born there in 1934.

Judi Dench's father Reginald Dench served in the first World War with the 7th Leinster Regiment. Photograph: BBC/Wall to Wall/Dame Judi DenchJudi Dench’s father Reginald Dench served in the first World War with the 7th Leinster Regiment. Photograph: BBC/Wall to Wall/Dame Judi Dench

There is a plaque with her father’s name at the Methodist Christ Church in Sandymount along with a stained glass window commemorating her grandmother Bessie Oak Dench, who died in 1932.

She has now agreed to be the honorary patron of the Prince of Wales’s Leinster Regiment (Royal Canadians) Association in memory of her father’s service in the first World War.

The regiment was disbanded in 1922 along with all the other Irish regiments in the British army after Irish independence. The association keeps the memory alive for the descendants of those who were in the regiment.

“I don’t know how to put into words my feelings on being asked to be honorary patron of the Leinsters,” Dench said. “To have a link in this way is better than anything I could ever imagine. I would be so honoured and so delighted.”

The Leinster Regiment recruited from the counties of Meath, Westmeath, Longford, Offaly (then King’s County) and Laois (Queen’s County), though during the first World War it widened its reach.

“We are thrilled as this is a great honour for us. It shows that the Leinsters are still a very strong family even though the regiment ceased to exist as a military unit in 1922,” said Paddy Kelly, chairman of the Irish Committee of the Leinster Regiment Association.