The disposition of Lt General Butler's III Corps over its 16 kilometres of front was in line with the policy of stronger on the left, weaker on the right.
When they had taken over this sector of the line from the French they had been assured that the Oise valley would form an obstacle to the Germans but this turned out not to be the case as it was almost dry.
58th Division had two of its brigades south of the river and the 173rd to the north. On the left of the 173rd was the 18th Division and these two formations (a total of four brigades) were covering almost three quarters of the Corps front. Opposite them von Hutier had assembled three divisions.
Von Hutier distributed his resources in mirror fashion to Butler and thus opposite the short northern sector held by Butler's 14th (Light) Division von Hutier massed a further four divisions.
Just after 0600 hours German infantry advanced along the northern banks of the Canal de l'Oise against 173rd Brigade whose four kilometre front line was held by one battalion: the 2/2nd London Regiment.
The Londoners fought doggedly throughout the day and although some positions were taken with the aid of tanks (The Germans used four of their own and five captured Mk Vs on the 21st March) others were still fighting on the evening of the 22nd when they were forced to surrender having being cut off and run out of ammunition.
A similar story developed across the front of the 18th Division where the 7th Buffs, 7th Royal West Kent and 8th Royal Berkshire Regiments were in the front line. The fog had allowed the Germans to get in and around many of the defensive positions which they then attacked from the rear. The British Forward Zone beat off many of the attacks and once swamped by numbers many of the small garrisons managed to fight their way out and rejoined the Battle Zone.
All along its short front the 14th Division were situated in an area that offered little in the way of natural defence and had dug a standard trench system occupied by three battalions in the forward line.
This disposition had caused some concern to their northern neighbours the 36th (Ulster) Division in XVIII Corps who felt that, deployed in this fashion as opposed to in depth, made their southern flank vulnerable.
The 14th Division were holding the high ground overlooking the valley of the Somme in which the 36th were situated. If the high ground around Essigny fell, the 36th's position would become precarious.
Following the bombardment the four German divisions advanced through the fog against the 14th Division taking the front line almost immediately as the Germans penetrated the area with ease.
Within a couple of hours the Battle Zone had been engaged and Urvillers had been cut off.
At Urvillers the 8th Bn KRRC held out until 1600 hours but the breach in the British lines had been made.
By mid afternoon the 7th Bn Rifle Brigade (A battalion its should be noted and not a real brigade) at Essigny le Grand had been forced to retire and the right flank of the Ulstermen was seriously at risk of being turned.
That evening General Gough decided that it would be necessary for III Corps to retire on the Crozat Canal which would force the 36th Division to pull back to the St Quentin Canal.