Brigadier-General John Frederick Hepburn-Stuart-Forbes-Trefusis, DSO (14 January 1878 – 24 October 1915), known as 'Jack Tre',[1] was a British Army officer in World War I.

[2] John Frederick Hepburn-Stuart-Forbes-Trefusis was born in 1878, the third son of Charles Henry Rolle Trefusis, 20th Baron Clinton (who had adopted by Royal Licence the surnames and arms of his first wife's family).

[5][8] It was a difficult time at Sandhurst, with pitched night-time battles between the companies when hockey sticks were used as weapons, and officers' leave was cancelled to deal with the unruly cadets.

[2] The Irish Guards went to France immediately as part of the British Expeditionary Force, and Trefusis joined them as a reinforcement on 18 September, following the battalion's heavy losses at Villers-Cottérêts during the Retreat from Mons and at the First Battle of the Aisne.

[1][19][20] Trefusis proved a popular and effective Commanding Officer,[1][21] who led the battalion through the battles of Neuve Chapelle and Festubert (where the Irish Guards again lost heavily), and during the trench and mine warfare around Ypres and Cuinchy.

[26] When Trefusis examined the German wire in front of his brigade on the evening before the attack, he found that it was largely uncut by the artillery bombardment and sent forward parties after dark to cut it by hand.

[28][29] At 01.00 the following morning, a strong German counter-attack pushed the brigade's advanced posts back to Gun Trench, which had been put into a state of defence.

After fierce hand-to-hand fighting, the leading Germans were thrown out of Gun Trench, which became the British front line.

The Irish Guards' historian recorded that Trefusis 'slips, or wades, through rain and mud to lunch with his old Battalion a few hundred yards away ... Then he goes on with the remnants of his shattered Brigade, to take over fresh work on a quieter part of the line, and en route to "get his hair cut".