The battalions' depleted ranks were made up with ordinary volunteers (and later conscripts) and although they retained the Public Schools titles, their exclusive nature was doomed.

In January 1915 the battalion was marched to a hutted camp at Woldingham, Surrey, with kit being moved by private cars and hired removal vans.

16th Middlesex was introduced to the trenches by 1st Middlesex of 19th Bde, a Regular Army brigade that had been transferred into 33rd Division to exchange experience[2][17][19][20][21] In its first tour of duty at the Annequin North trenches on 2–14 January the battalion suffered its first casualties, losing one officer and 11 other ranks (ORs) killed, with 24 ORs wounded by a single shell.

Then when the battalion was in brigade reserve on the night of 3/4 February, it was ordered to make a bombing attack on three craters at Mine Point.

On 16 February the Germans exploded a large mine; a party of 16th Middlesex held the lip of the crater until relieved by 21st Royal Fusiliers (4th Public Schools).

[8][9][2][17][22][23] On 25 February the public schools battalions were withdrawn from 33rd Division and assigned to GHQ Troops at Saint-Omer while their best men were selected for officers' commissions; 16th Middlesex supplied 250 candidates.

The rest of the battalion was then quarantined at Saint Omer due to an outbreak of German Measles, and it was not until 24 April that it entrained for Doullens, made up to strength with raw recruits.

The division's objective was to cross 350 yards (320 m) of open ground and penetrate the German front line to Beaumont-Hamel, taking the Hawthorn Ridge Redoubt with the assistance of a large mine.

Controversially, the Hawthorn Ridge mine was blown at 07.20, 10 minutes before Zero hour, which allowed the Germans time to recover before the infantry went 'over the top'.

[23][24][25][30][31][32][33][34] Before dawn on 1 July 16 Middlesex under Lt-Col Hall moved up to assembly trenches named Cripps Cut and Cardiff Street, where they waited while the first wave went forward into No man's land five minutes before Zero.

The barrage was so intense and the number of returning wounded so great that the second wave, including B and D Companies of the 16th Middlesex, could not leave their trenches until 07.55.

Malins' film shows a distant group of men, believed to be from the 16th Middlesex, reaching the crater, then retreating in smaller numbers.

The following night three platoons of A Company and three from the 1st Lancashire Fusiliers advanced under a 'pocket barrage' to push outposts across the troublesome Steenbeck stream (which had halted earlier attacks) and take Passerelle Farm.

[24][25][64][65][66] On 16 October 29th Division was moved south by rail to train for the great tank attack on the Hindenburg Line (the Battle of Cambrai).

About 16.00 a platoon of 16th Middlesex with one tank captured a bridge across the St Quentin Canal and linked up at Noyelles-sur-Escaut (already entered by the cavalry) with 2nd Royal Fusiliers which had fought its way past Marcoing.

Although the British guns supported as best they could, the Germans had broken through the neighbouring brigade and were streaming towards Marcoing and the battery positions in large numbers.

The Germans did not renew their attacks in the afternoon, but 16th Middlesex remained under heavy artillery and machine gun fire; as the Official History relates: '[t]his Battalion bore its ordeal with amazing fortitude, heartened by its commanding officer, Lieut.-Colonel J. Forbes-Robertson, who visited all positions in turn even when, blinded by a wound, he had to be led by hand'.

Having been forced into an untenable salient along the canal by the previous day's fighting, the brigade had to be either reinforced or withdrawn, but it was not until 19.00 that word got through to pull out.

The withdrawal was completed by 04.00 on 2 December, and the brigade was sent for well-earned rest in Ribécourt-la-Tour while the Germans continued to shell their empty positions at Masnières.

[87][88] By early 1918 the BEF was suffering a severe manpower shortage: roughly one in four infantry battalions had to be disbanded and their surviving personnel drafted to reinforce other units.

All the infantry of the division were concentrated at Clipstone by 13 July and on 3 August they moved to Salisbury Plain for final battle training, with 98th Bde at Tidworth Camp.

After only a short period learning the routines of trench warfare the 18th, 19th and 21st Battalions were all transferred to GHQ Troops on 27 February 1916 and disbanded on 24 April, when the majority of their personnel were commissioned as officers (see above).

Captain Robert Graves of 2nd Bn Royal Welch Fusiliers, also in 19th Bde, was highly critical of the battalion: 'Their training had been continually interrupted by the large withdrawal of men needed to officer other regiments.

One night he visited the front line when an apparent German raiding party was detected: after a flare and a few machine gun rounds had been fired over their heads the 'raiders' surrendered and turned out to be a large patrol from the public schools battalion that had been wandering aimlessly in No man's land.

20th Royal Fusiliers, following close behind, cleared the southern part of the objective, but the losses in senior officers led to confusion in the brigade.

With fresh support, 20th Royal Fusiliers then reached the northern part after hard fighting, but were driven back to the southern half by high explosive and gas shelling before relief could arrive.

[2][17][101][102] 33rd Division was rested until the night of 6/7 August when it returned to the High Wood sector to carry out engineering preparations for the next attack on 'Wood Lane'.

It arrived on 31 July and spent the next three weeks under shellfire – both high explosive and Mustard gas – and nightly air raids, as well as repelling one serious attack on 19th Bde, but by the end of August it was clear that the BEF was not going to achieve a clean breakthrough, and the units on the coast began to be sent to the Ypres Salient to reinforce the offensive there.

[2][17][117][118] In November 1917 the 33rd Division was moved to the north of Ypres to take over the Passchendaele Salient from the Canadians, and spent the winter months taking turns of duty in this, probably the worst area on the Western Front, a sea of mud with no cover, with appalling trackways to traverse to and from the line, and under persistent shellfire, particularly with mustard gas shells.

[119] Like the 16th Middlesex, the 20th Royal Fusiliers was disbanded between 2 and 15 February 1918, when 19 officers and 520 ORs were posted to other battalions, and the remainder sent to VIII Corps' Reinforcement Camp.