This post will look at regimental numbering in the 5th (Extra Reserve) Battalion of the Royal Munster Fusiliers between 1908 and 1914. The Special Reserve and the Extra Reserve were the natural heirs to the militia battalions which, for the most part, they replaced in 1908. My 2009 article on the Creation of the Special Reserve in 1908 may be helpful here.
The Royal Munster Fusiliers had three militia battalions (the 3rd, 4th and 5th Battalions) and these survived in all but name when the Special Reserve was introduced in 1908. Men who were then serving with the 3rd (Militia) Battalion, were asked if they wanted to continue to serve with the newly formed 3rd (Special Reserve) Battalion, and men who were then serving with the 4th and 5th (Militia) Battalions, were asked if they wanted to continue to serve with the newly formed 4th & 5th (Extra Reserve) Battalions.
Men joining the militia and special/extra reserve were not career soldiers. The Army Book for the British Empire, published in 1893 provided a useful overview of the militia when it noted:
"Its object is to maintain in the United Kingdom a trained body of men available "in case of imminent national danger or great emergency" to supplement the regular army in the defence of the country.
"It offers military service to the class of men willing to give it for a month in the year for training of for the term of their engagement on emergency, but whose avocations do not lead them to become either regular soldiers or volunteers."
Most 1914 Star rolls show plenty of evidence of Special Reserve and Extra Reserve men who served alongside career soldiers. Sometimes their numbers are prefixed by the number of their battalion - typically a 3/ or 4/ in most line infantry regiments - but just as often there will be no prefix.
In 1908 the regular battalions were numbering in the 8000 range whereas the 5th Battalion, picking up the old militia numbering sequence, was numbering in the 5000s. When these 4th Battalion men were called up as drafts for the regular 1st and 2nd Battalions from August 1914, they retained their original 5th Battalion regimental numbers.
Here are some sample regimental numbers and joining dates for the 5th Royal Munster Fusiliers. Use this information to estimate when a man would have joined this battalion.
5319 joined on the 28th December 1908
5357 joined on the 28th February 1909
5529 joined on the 16th May 1910
5629 joined on the 17th February 1911
5845 joined on the 7th November 1912
5994 joined on the 12th December 1913
6031 joined on the 14th April 1914
6119 joined on the 18th August 1914
6216 joined on the 15th September 1914
Do also read of some of the articles towards the bottom of the Army Service Numbers 1881-1918 index.