Hi historians of Reddit! I’ve got a question on how British units were reinforced in WWI.
In the movie 1917, Blake had no idea Schofield was a Somme veteran despite being in the same unit until Schofield mentions his trading away his Somme medal.
It doesn’t seem like their current unit fought at the Somme, so seemed likely to me that Schofield was reassigned.
I know the US Army replaced entire depleted battalions with new ones during WWII to maintain unit cohesion and only sent fresh soldiers to reinforce existing units in Vietnam due to a lack of manpower, but what was the reinforcement policy like for the UK in WWI?
Ok, late reply but your question intrigued me. I can't give you a massively detailed answer, but I can help you get on the right track. Based on the insignia on Blake's helmet and dialogue from the screenplay, it appears Blake and Schofield are a part of the 8th Service Battalion of the East Surrey Regiment, which during the war was a part of the 55th Brigade of Ivor Maxse's 18th (Eastern) Division. It was what was known as a Hostilities-only battalion, meaning it was raised only "for the duration", rather than being a regular army unit.
It's mentioned that Schofield was at the Somme - he specifically mentions taking part in the fighting of Thiepval, which the 18th Division, part of Jacob's II Corps, did indeed take part in. So, we can take all that to assume that Blake is a reinforcement to the 18th - he's been in the army long enough to pick up a stripe, but his characterization implies he's seen little to no combat, so it's possible he was promoted because it's mentioned he's good as a scout/runner.
(As a side note, the 8th Surrey's have gone down in the history of the Somme for their "football charge", in which two officers went over the top on July 1st kicked footballs.)
Source: http://www.queensroyalsurreys.org.uk/1661to1966/ww1-east/ww1-east-surreys.shtml
