Returning to Egypt, Hart was heavily involved with the training of his command, which included a substantial number of replacements.
He was also required to divest a number of his more experienced officers and non-commissioned officers to help with the formation of the 2nd Battalion of the Wellington Regiment.
 His battalion was subsequently re-designated as the 1st Battalion, Wellington Regiment, while the New Zealand Infantry Brigade was reformed as the 1st Infantry Brigade.
The brigade was one of the three infantry brigades to make up the newly formed New Zealand Division, intended for service on the Western Front and it was duly shipped to France in April 1916.

The division was initially based near Armentières and Hart's battalion was among those manning the trenches in the sector.
The battalion had to contend with artillery and repelling localised attacks and raids by the opposing Germans.
 Hart organised a counter-raid to be conducted by his battalion, and this was successfully executed on 1 July.
The division would remain in the Armentières sector until August 1916, at which stage it was withdrawn for use in the forthcoming Somme Offensive in September.
Hart led his battalion during the Battle of Flers-Courcelette and the subsequent period in the trenches, and was mentioned in despatches for his work during this time.
 He also had spells as temporary commander of the brigade while Johnston was on leave, and from December 1916 to January 1917 was in command of 3rd New Zealand (Rifle) Brigade.

In March 1917, Hart was promoted to brigadier general and appointed commander of the newly formed 4th Infantry Brigade.
The new brigade was intended for service with the New Zealand Division.
 After a brief training period in England, the brigade was transferred to France for further training and a period in the front line.
In October, it saw service during the successful attack on the Abraham Heights on the Gravenstafel Spur in what was known as the Battle of Broodseinde and was commended for its services by both Godley, still commanding the NZEF, and the commander of the New Zealand Division, Major General Andrew Russell.
 The brigade was in reserve for the subsequent First Battle of Passchendaele, and, apart from a brief period in training, would remain in the Ypres sector until January.
He was mentioned in despatches for his work with the 4th Infantry Brigade while it was on the front line.

Hart was made commander of the 2nd Infantry Brigade when the 4th Brigade was disbanded in February 1918.
He was mentioned in despatches for his work with the 4th Infantry Brigade while it was on the front line.
His new brigade absorbed many of the soldiers of his previous command.
However, on 18 February, just two weeks after taking command, he was badly gassed during an artillery barrage on his headquarters.
The barrage, using a mixture of high explosive and mustard gas shells, also incapacitated most of his staff.
Temporarily blinded, he was evacuated to a hospital in the rear and then to Étaples.
After recovering his sight, which took about a week, he was dispatched to the south of France to convalesce.

Upon recovery from the effects of his gassing, and aided by the temporary presence of his wife Minnie, Hart returned to England and was placed in command of the New Zealand reserves at Sling Camp in Bulford.
Here he was responsible for the training of reinforcements and casualties who were regaining fitness.
On 3 June, his leadership of the 4th Brigade was honoured with an appointment as a Companion of the Order of St Michael and St George, although he took little personal satisfaction in the recognition.

Hart's duties at Sling Camp ended in July, when he was recalled to France to take over command of the 3rd New Zealand (Rifle) Brigade.
He led the brigade through the Hundred Days Offensive, which included an action during the Second Battle of Bapaume that impressed his commanding officer, Russell.
During the battle, Hart's headquarters was again shelled with mustard gas.
After his previous experience of being gassed, Hart found the s
Returning to Egypt, Hart was heavily involved with the training of his command, which included a substantial number of replacements. He was also required to divest a number of his more experienced officers and non-commissioned officers to help with the formation of the 2nd Battalion of the Wellington Regiment.  His battalion was subsequently re-designated as the 1st Battalion, Wellington Regiment, while the New Zealand Infantry Brigade was reformed as the 1st Infantry Brigade. The brigade was one of the three infantry brigades to make up the newly formed New Zealand Division, intended for service on the Western Front and it was duly shipped to France in April 1916.
The division was initially based near Armentières and Hart's battalion was among those manning the trenches in the sector. The battalion had to contend with artillery and repelling localised attacks and raids by the opposing Germans.  Hart organised a counter-raid to be conducted by his battalion, and this was successfully executed on 1 July. The division would remain in the Armentières sector until August 1916, at which stage it was withdrawn for use in the forthcoming Somme Offensive in September. Hart led his battalion during the Battle of Flers-Courcelette and the subsequent period in the trenches, and was mentioned in despatches for his work during this time.  He also had spells as temporary commander of the brigade while Johnston was on leave, and from December 1916 to January 1917 was in command of 3rd New Zealand (Rifle) Brigade.
In March 1917, Hart was promoted to brigadier general and appointed commander of the newly formed 4th Infantry Brigade. The new brigade was intended for service with the New Zealand Division.  After a brief training period in England, the brigade was transferred to France for further training and a period in the front line. In October, it saw service during the successful attack on the Abraham Heights on the Gravenstafel Spur in what was known as the Battle of Broodseinde and was commended for its services by both Godley, still commanding the NZEF, and the commander of the New Zealand Division, Major General Andrew Russell.  The brigade was in reserve for the subsequent First Battle of Passchendaele, and, apart from a brief period in training, would remain in the Ypres sector until January. He was mentioned in despatches for his work with the 4th Infantry Brigade while it was on the front line.
Hart was made commander of the 2nd Infantry Brigade when the 4th Brigade was disbanded in February 1918. He was mentioned in despatches for his work with the 4th Infantry Brigade while it was on the front line. His new brigade absorbed many of the soldiers of his previous command. However, on 18 February, just two weeks after taking command, he was badly gassed during an artillery barrage on his headquarters. The barrage, using a mixture of high explosive and mustard gas shells, also incapacitated most of his staff. Temporarily blinded, he was evacuated to a hospital in the rear and then to Étaples. After recovering his sight, which took about a week, he was dispatched to the south of France to convalesce.
Upon recovery from the effects of his gassing, and aided by the temporary presence of his wife Minnie, Hart returned to England and was placed in command of the New Zealand reserves at Sling Camp in Bulford. Here he was responsible for the training of reinforcements and casualties who were regaining fitness. On 3 June, his leadership of the 4th Brigade was honoured with an appointment as a Companion of the Order of St Michael and St George, although he took little personal satisfaction in the recognition.
Hart's duties at Sling Camp ended in July, when he was recalled to France to take over command of the 3rd New Zealand (Rifle) Brigade. He led the brigade through the Hundred Days Offensive, which included an action during the Second Battle of Bapaume that impressed his commanding officer, Russell. During the battle, Hart's headquarters was again shelled with mustard gas. After his previous experience of being gassed, Hart found the s
Herbert Ernest Hart