The 150^th Infantry Brigade was occupying the Plateau de Californie (or Cranonne Plateau) with the right at Chevreux Village and the left Piste D.Orleans inclusive. Total front line about 2400 meters (2600 yards).

Two battalions were on the frontline 5^th Btn Yorks Regt on the right and 4^th Btn East Yorks on the left. 4thy Btn Yorks Regt was in divisional reserve at Beaurieux. Of the frontline battalions the 5^th Btn Yorks Regt on the right with three companies in front and one in reserve alternated with 4^th Btn Yorks Regt for tour of six days. The 4^th Btn East Yorks Regt on the left remained permanently in the line on a single company front.

On a warning being received from Division about 4:00pm of an impending hostile attack reported by prisoners to open with a two or three hour bombardment at 1:00am 27^th, the following measures were taken:-

1) the reserve company of 4^th Btn East Yorks was moved from La Hutte to P.C. Verdun (in Craonne) and placed at the disposal of the 5^th Yorks.

2) the support company of the4th East Yorks moved from Electra into close support in Trench Falaise (just under S. crest of the Plateau)

3) The 4^th Bn Yorks Regt having been released from Divisional reserve and placed at the disposal of the Brigade was directed into the line Mt Hermel to Tr Behart (500 yards north of Crannoelle), along which line dugouts to accommodate the battalion had been recently clear and rendered habitable.

Harassing fire had been carried out during the early part of the night by our artillery and machine guns, on the enemy approaches upon abnormal activity had been noticed during the evening of the 26^th. At 1:00 AM the bombardment opened with all nature of shell including gas. Brigade HQ’s in particular were shelled inconsistently with gas and masks had to be worn outside the gas proof dug outs. All communications were cut within a very short time, except buried cables. These existed to Btn HQ & observation posts on the Plateau. The bombardment was the heaviest yet experienced and heavy casualties were caused in the forward posts on the Plateau.

The infantry attack developed against the Brigade front from the north. But as a result of the successful advance made by the enemy on the right position of the Divisional front and through the 22nd French Division on the left the plateau was enveloped on both flanks by about 6.30am. The hostile barrage was maintained on the plateau itself to the east and it is feared that many men what captured in the deep dugouts before they were able to come out.

The O.P’s on the plateau had been unable to report the progress of events owing to the smoke and dust, there was no morning mist. The buried cables to the right Battalion held & Lt Col Thomson reported about 5.45am that his Headquarters Company were then fighting around his command post and that they appeared to be surrounded. No news was received from the 4^th East Yorks, very few of those men came back, but it is probable that they were overwhelmed about the same time.

The Brigadier General Commanding decided in view of the general advance being made by the enemy along the whole front that no counter attack carried out by the 4^th Yorks could be expected to meet with success. He intended therefore to hold the intermediate line with his battalion, moving his Headquarters back to P C Terrasee (600 yards S of Craonnelle) to which proposal the Divisional General agreed by telephone. On arrival there however it was discovered that the 4^th Yorks have been overwhelmed on the Mt Hermel-T R Behart line and that the enemy were already approaching P C Terrasse from the West. An attempt to organise into defence at this point had therefore to be abandoned.

Brigade Headquarters have now become dispersed as a result of hostile shelling. The Staff Captain and the Intelligence Officer had been wounded earlier in the morning and the Brigade Major was wounded whilst withdrawing towards the Aisne. Brigadier General Rees, it is believed, became too exhausted to continue and was captured. Some few stragglers were collected on the River [Aisne] and placed under such officers as could be found. The Brigade Headquarters ceased to exist temporarily and was not reformed until the arrival of the division at Vert-la-Gravelle on the 31st May.