British regimental number research. First World War research. Military research. British Army regiments. Regimental numbering sequences between 1881 and 1918. Regimental number series. Other rank prisoners of war 1914.
I've updated the data for the 6th Essex Regiment, giving further examples of army service numbers and joining dates up until 1916, explaining how men enlisting for local guard and supernumerary company duty were numbered (and then re-numbered) and giving sample numbers and joining dates from the six digit series allocated to the 6th Battalion in 1917.