The 2nd Battalion Royal Fusiliers (City of London Regiment) were in Calcutta. India when war broke out in August 1914.As soon as a territorial unit arrived to take over the garrison. they departed for England, arriving in December and joining 86th Brigade. 29th Division at Nuneaton. They were training for France when the order arrived to prepare to depart for Gallipoli. They embarked from Avonmouth between the 16th and 22nd of March 1915 sailing via Malta to Alexandria then on to Mudros in April. They landed at Cape Helles, Gallipoli on the 25th of April 1915 and were involved in heavy fighting until the evacuation on the nights of the 7th and 8th of January 1916 when they returned to Egypt.

It's not clear where or how Thomas died, but it is likely that he died in a field hospital of injuries sustained either during a bombardment from the Turkish forces, or during an attack on a sap (i.e. a trench). The summary war diaries don't note any specific assault or enemy fire on 9 Nov 1915, and the previous assault was made on 16 Oct 1915 and 17 Oct 1915.