I went to see the movie 1917 last week. There were several trench scenes where blacks were serving in the trenches with the main characters' battalion and there was a scene on a truck where there is Sikh soldier who was a member of another British battalion.
I know that a large number of Indians, West Indians, and Africans served with the British Army in Europe during World War I. My understanding is however that they were not in the regular British infantry regiments, but served in either infantry and cavalry regiments in the Indian Army or in the case of the blacks were in their own units, usually in service / support units.
Is this true? If so, when did the British Army started integrating their regiments? Post World War II?
There was Lieutenant Daniel Tull who served in the Middlesex Regiment in the Footballers Battalion, but was he an exception?