I am researching my ancestor, and it appears that he was in the 16th, although this isn't definite. Can anyone give me details about where they fought prior to 1917 (he was wounded and transferred to hardelot on 2 sep. 1916, and transferred to labour corps) and maybe provide some photos of the 16th? Any guesses to which battle he may have fought in judging off of his regiment and date of injury? Anything useful is greatly appreciated, thanks!
What a small world it is — two of my great-great-uncles served in the Royal Warwickshire Regiment and were killed in action. At least one of them was in the 16th battalion (I think they actually both were, but I can't find the CWGC record for the other right now.)
The massive expansion of the army during the First World War played havoc with conventional regimental naming and numbering schemes, which can make tracing their wartime records something of a headache: first, because one regiment might have swelled to 20 or 30 battalions during the war: usually two regular army battalions, possibly another one or two Territorial battalions, plus potentially dozens of 'New Army' battalions — each of which commonly had their own local or regional designation. Regiments were seldom deployed in full in any one theatre: at any given time during the war, some of the regiment's battalions might be in France; others might be at home, and others still might be in North Africa or the Middle East.
So, to get to the point: the proper title of the unit in question is actually the 16th (Service) (3rd Birmingham) Battalion, Royal Warwickshire Regiment. The 14th, 15th and 16th were City of Birmingham 'pals battalions' — meaning they were recruited from specific communities, neighbourhoods, trades or professions. There's a book about the Birmingham Pals (part of a series about the pals battalions) that you might want to track down. It's been a long time since I've looked at the book, however, so I can't vouch for its quality. You should also check out this website, and perhaps get in touch with whoever runs it.
I know some of my relatives did some pretty expansive research into their wartime service a few years back, but it's been ages since I've seen any of it — I'll see if I can get my hands on any of their notes. In any case: I know the 16th were at the Somme in the summer of 1916, at Passchendaele in summer/autumn 1917, but I haven't got much more specific detail than that to hand.
As a general rule, it's often easier to trace units' movements at the brigade or division level. Here's the 16th's organisational history, from this page:
Hope that helps in some small way — good luck with the search!