This page describes one of the 21 battle honours won by the 15th Battalion CEF and it is one of 10 that are emblazoned on the Regimental colour.
The battle honour covers actions conducted between 1 September and 14 October 1916. During this timeframe the 15th Battalion was additionally awarded three other battle honours Pozieres (3 September), Thiepval (26-27 September) and Ancre Heights (5 October).
For more information see Mount Sorrel on the Canadian War Museum web site.
The Battles of the Somme July – Nov. 1916