Highgate School is to open a museum commemorating its part in the First World War – exactly 100 years after the death of a teacher believed to be the first educator killed in the conflict.

Saturday marked the centenary of the death of 2nd Lt A.J.N. Williamson, a Highgate School pupil turned teacher who died less than two months after the war began.

The independent school, in North Road, Highgate, will remember the 25-year-old soldier amongst others who lost their lives in the First World War in its new museum, which is due to open to the public on one day a week from January next year.

Details of the museum, which will document nearly 500 years of school history, are currently under wraps but a crowdfunding campaign to raise money for the venture will launch in the next few weeks.

School archivist and records manager Julia Hudson came across 2nd Lt Williamson’s story while preparing for the museum’s opening.

She said: “He felt the call to fight for his country and joined up the day after war was declared.

“One can only feel great admiration for him, like for so many others who fought and died in the war.

“It is happening upon stories such as Williamson’s in the school’s archives that makes the job of an archivist so rewarding.”

2nd Lt Williamson, who was born in December 1888, won several silver sports medals and a bursary to the University of Cambridge during his time as a pupil at Highgate School.

His time with the British Army began at the age of 15 in 1903 as a drummer but he marched through the ranks to become colour sergeant until he resigned to take up his place at Pembroke College, Cambridge.

In 1912, he returned to Highgate School as a teacher having rejoined the army’s Seaforth Highlanders regiment a year earlier.

In the November 1914 issue of the school’s magazine, The Cholmeleian, an obituary said of him: “His keenness and knack for clear exposition at once riveted everyone’s attention and his grasp of his subject commandeered their confidence.

“He was a born leader who never lost his head or his temper. To all of us his death causes unspeakable regret.”

2nd Lt Williamson was shipped to Boulogne on August 23, 1914, almost a month after he signed up to fight in the war.

He and his regiment were rushed to the front line the following morning and his letters describe how they marched ceaselessly with just an hour’s sleep in one day.

On September 12, the regiment received sudden orders to get to the front line again.

Two days later at the Battle of Aisne, 2nd Lt Williamson was killed instantly by a shell.

Ms Hudson said: “As a community, the school can, to some extent, understand the tremendous sadness pupils and staff must have felt upon hearing the news of his death at the Battle of Aisne.

“At the time, some described his loss as ‘simply irreparable’, while others could not find the words to pay him adequate tribute.”