THIS DAY IN RMR HISTORY – August 5, 1914: After being ordered to combine their forces, and following a series of meetings involving the Grenadier Guards, the Victoria Rifles, and the Carabiniers de Mont-Royal, an active service battalion was created. The Canadian Minister of Defence, Col. Hon. Sam Hughes, bestowed on the new unit the title “Royal Montreal Regiment” and under this name the battalion fought in France. At the time the use of the word Royal was not legitimate. Officially the warrant to use the royal prefix was granted by King George only after the Regiment had established its worth in battle and had returned to Canada. In the meantime the title “Royal Montreal Regiment” was used to designate the Battalion in the Army List issued by the War Office. 
In Europe, this day began with the opening land battle of the war when the German Second Army, following the German “Schlieffen Plan,” crossed the frontier into neutral Belgium in order to attack France from the north. This was the first time since 1839 that German troops had entered Belgium. This opening attack was to become known as The Battle of Liege. It lasted from August 5th to 16th 1914.
The Montreal Daily Mail, August 5, 10914, pg. 1.
Featherstonhaugh, R.C., The Royal Montreal Regiment 14th Battalion C.E.F. 1914-1925, pg. 5