Formed at Herne Bay 1 January 1917, from the 84th Provisional Bn became 17th Bn TF. The 84th was formed from Home Service personnel from the TF Bns of the regiment. Under Colonel Peters the Battalion was deployed in home defence duties in the 227th Brigade

227th Brigade.

35th Bn Northumberland Fusiliers. 01 Jan 1917 - 11 Nov 1918.
15th Bn Devonshire Regt. 01 Jan 1917 - 11 Nov 1918.
11th Bn Somerset Light Infantry. 01 Jan 1917 - May 1918. To the 59th Division .
13th (Home Service) Bn Somerset Light Infantry. 27 Apr 1918 - 11 Nov 1918.
17th Bn Hampshire Regt. 01 Jan 1917 - 11 Nov 1918.
2/25th Bn London Regt. Mar 1918 - 11 Nov 1918.