The order of battle of Brigade was as follows:

169th Brigade (right):
Front line system:Queen's Westminsters in Towy Post on the right.
London Rifle Brigade in Mill,
Bradford and Bird Posts on the left.
Red line:1/2nd Londons.
Brown line:1 coy. 1/5th Cheshire Pioneers.
Reserve:2 coys. 1st Londons (attd. from 167th Brigade).
168th Brigade (left):
Front line system:1/4th Londons in Beatty, Wood and Oppy Posts on the right.
Kensingtons in Tommy and Arleux Posts on the left.
Red line:London Scottish.
Brown line:2 platoons 1/5th Cheshire Pioneers.
Green line:2 coys. 1st Londons, 1½ coys. 1/5th Cheshire Pioneers.
Divisional Reserve:
167th Brigade (less 1st Londons) and 3 field coys. R.E.

The companies of the 1/4th Londons were disposed as follows:

Right:B Company (Spicer) H.Q. and 2 platoons in Beatty Post. 1 platoon in Marquis and Earl line.
Centre:C Company (Duthie) 1 platoon in Wood Post. 1 platoon in Marquis line. H.Q. and 1 platoon in South Duke St.
Left:A Company (H. N. Williams) 1 platoon in Oppy Post. 1 platoon between Oppy Post and Marquis line. H.Q. and 1 platoon in Marquis line.
Advanced Battalion H.Q.:(Major F. A. Phillips) in South Duke St. (with C Coy.)
Support:D Company (Cooper) in Bow Trench.
Battalion H.Q.:(Lieut.-Col. Marchment) in Ouse Alley west of Bow Trench.

During the night 2/Lieut. R. E. Campkin with two men of C Company again crossed No Man's Land and returned shortly before 3 a.m. on the 28th March reporting that he had seen long lines of men carrying up to the enemy front line what appeared to be large biscuit tins—doubtless the trench mortar ammunition coming in. Evidently this was The Day!

At 3 a.m. on the 28th March the enemy opened an intense high explosive shell fire on Bow Trench, Ouse Alley and Rear Battalion Headquarters, as well as on all the rearward defensive posts. This bombardment, which continued throughout the day, was at first mingled with mustard gas. The forward area was hardly affected by this shelling except for the fact that the wind carried the gas eastward over the front line posts, the garrisons of which had to wear masks for over an hour.

At 5.40 a.m. a terrific trench mortar fire fell on the forward posts doing very severe damage, and causing many casualties. Ouse Alley and the Earl-Marquis line at first escaped this, though later the area of bombardment was extended and they received a full share of it.

A strictly chronological account of an action such as this, in which different parts of the Battalion became involved in the fight at varying hours, is almost an impossibility if the reader is to glean anything but the most confused impression of what occurred. We propose, therefore, to deal first of all with the fight for the front line posts gradually working our narrative westward.

The S.O.S. signal was received in Battalion Headquarters from Oppy Post by wire at 7.15 a.m., and a few moments later flares were sent up from Wood and Beatty. The signal was repeated backwards to Brigade by Battalion Headquarters. "We stood on top," writes Lieut.-Col. Marchment, "to have a look round but could see very little as it was not fully light. We could, however, hear a pleasant noise—very heavy rifle fire!"

Oppy Post on the left had been very badly knocked about by the trench mortaring and the garrison seriously reduced before the enemy came over. A gallant attempt at resistance was put up and rifle and Lewis gun fire were opened as soon as the attacking lines made their appearance. One Lewis gun team was seen from the rear to have climbed on to the parapet, and the gun was being fired from the hip. But it was hopeless from the first. The enemy lines were very close, and by sheer weight of numbers the Post was quickly swamped. Of a garrison of 2 officers and 48 other ranks but 1 officer (2/Lieut. Athey) and 5 other ranks were able to make their way back to the Marquis line which they did by way of Boyne Trench.