The 7th Battalion of the London Regiment was known as the Shiny 7th. The battalion was associated geographically with the City of London, hence their full title was the 7th (City of London) Battalion of the London Regiment. It is no wonder that they had a much shorter nickname!
In common with how most other battalions were organised in the First World War, there were three battalions of the Shiny 7th: the 3/7th was the training battalion, which provided soldiers for the front line battalions, the 1/7th and 2/7th.
The 3/7th was based in Sutton Mandeville from January 1916 to late July 1916. They created the Shiny 7th badge in March-April 1916.
The Shiny 7th took part in several actions in the latter part of the Somme Offensive in autumn 1916. They suffered heavy losses in harrowing circumstances. Soldiers who trained at Sutton Mandeville are known to have been amongst the casualties.
Further information about the 3/7th can be found in the posts below:
Posts about the 3/7th London Regiment