Family History.
Search war diaries online.
From the site:
Wouldn’t it be fascinating to discover what your First World War ancestor’s army unit actually did?
War Diaries are official daily accounts kept by individual units. They give reports on operations, intelligence summaries and other material. They can help you piece together your ancestor’s life in the army in the First World War.
Search the diaries here
Searching is free and you only pay for downloads.
Source: National Archives, UK