On 20 August the entire division moved to Chelmsford, Bury St Edmunds and Norwich.

The division spent the next few months on home service and coastal defence and started training in preparation to eventually go overseas.

As happened in all Territorial Force divisions, the battalions were also numbered and adopted the '1/' prefix (1/4th Suffolks), to distinguish them from their 2nd Line units which were being formed.

In November 1914 the 1/4th Battalion, Suffolk Regiment was transferred to the 3rd (Lahore) Division of the British Indian Army and were replaced in the brigade by the 1/8th (Isle of Wight Rifles) Battalion, Hampshire Regiment, which was previously unattached to a field formation.

The brigade served with the 54th Division in the Middle Eastern theatre and fought in the Gallipoli Campaign, landing at Suvla Bay on 10 August 1915, as part of IX Corps.

During the fighting on 12 August the 1/5th Norfolks "...were on the right of the line", wrote Sir Ian Hamilton, commanding all forces in the region "and found themselves for a moment less strongly opposed than the rest of the brigade.

Against the yielding forces of the enemy Colonel Sir Horace Beauchamp, a bold, self-confident officer, eagerly pressed forward, followed by the best part of the battalion.

The division was evacuated from Gallipoli in early December and spent the most of 1916 in Cairo, Egypt, occupying No.

However, it was reformed, as the 163rd (Norfolk and Suffolk) Infantry Brigade,[4] in the Territorial Army and continued to serve with the 54th (East Anglian) Division and had the same four battalions as it did before the First World War.