The raising of 21 new Siege Batteries of the Royal Garrison Artillery was authorised by Army Council Instruction 1639/1916, with effect from 12 August 1916.
| RGA Battery | Raised at |
|---|---|
| 222 Siege Battery | Portsmouth |
| 223 Siege Battery | Tynemouth |
| 224 Siege Battery | Plymouth |
| 225 Siege Battery | Dover |
| 226 Siege Battery | Weymouth |
| 227 Siege Battery | Pembroke Dock |
| 228 Siege Battery | Forth |
| 229 Siege Battery | Harwich |
| 230 Siege Battery | Hartlepool |
| 231 Siege Battery | Tay |
| 232 Siege Battery | Liverpool |
| 233 Siege Battery | Newhaven |
| 234 Siege Battery | Portsmouth |
| 235 Siege Battery | Mersey |
| 236 Siege Battery | Cardiff |
| 237 Siege Battery | Humber |
| 238 Siege Battery | Sheerness |
| 239 Siege Battery | Portsmouth |
| 240 Siege Battery | Dover |
| 241 Siege Battery | Portland |
| 242 Siege Battery | Sheerness |