Background
In early 1917, three of the brigades of the Royal Horse Artillery were taken out of the command of a division, and became an Army Brigade. From that point onwards, they could be moved from division to division as operational needs arose. This can make things difficult for a researcher even if their own war diary exists.
Luckily, some information about the movements of the Army Brigades has been compiled for the brigades. The source of the following information is National Archives piece WO95/5494.
Army Brigades
V Army Brigade RHA
XIV Army Brigade RHA
XVI Army Brigade RHA
XVII Army Brigade RHA
This is the one Army Brigade RHA not covered in WO94/5494. Its time as such was however brief, for it became so in late March 1918 and ceased to exist on 9 April 1918.