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Instituted:
1830
Qualification:
The Army Long Service & Good Conduct (LSGC) medal was originally awarded to infantry NCOs and men who had completed 21 years' good conduct, or cavalry NCOs and men who had completed 24 years' good conduct. In 1870 the qualifying period was reduced to 18 years for both the cavalry and the infantry.
Description:
Silver, 36mm diameter. The metal and the size appear to be the only characteristics of the medal that remained unchanged over the years. The following information comes from a variety of sources.
1830-1831
King William IV - type 1 (small ring)
The medal was designed by by Benedetto Pistrucci (1783-1855). His most famous design was that of St George slaying the dragon, an image that first appeared on British gold sovereigns and crow in 1817 and is still in use today. The obverse depicts the royal coat of arms with a small shield of the House of Hanover, surrounded by a trophy of arms. The reverse carries the legend, FOR / LONG SERVICE / AND / GOOD CONDUCT. (See image below, courtesy of Dixons Medals)
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1831-1837
King William IV - type 2 (large ring)
Same as above but with a large ring.
1837-1855
Queen Victoria - type 1 (Hannoverian emblem dropped)
On the accession of the new queen, the Hannoverian emblem was dropped and replaced by Queen Victoria's Royal coat of arms (see image at the top of this post), although new dies were not introduced until 1839. The legend on the reverse remained the same.
1855-1874
Queen Victoria - type 2 - (swivelling scroll suspension)
A swivelling scroll suspension was introduced in 1855. (See image below, courtesy of Dixons Medals).
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1874-1901
Queen Victoria - type 3 (smaller lettering)
Swivelling scroll suspension and smaller lettering on the reverse replacing the larger lettering. (See image below, courtesy of Dixons Medals).
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King Edward VII
Since 1901, Queen Victoria's coat of arms has been replaced with the head or bust of the reigning monarch. The obverse of the King Edward VII version portrays the bust of the King (facing left) in field marshal's uniform with the legend EDWARDUS VII REX IMPERATOR. The reverse carries the legend, FOR / LONG SERVICE / AND / GOOD CONDUCT.
1911-1920
King George V - type 1
The obverse depicts the bust of King George V (facing left) with the legend GEORGIUS BRITT: OMN: REX: ET: IND: IMP: (George V, omnipotent King of Great Britain and Emperor of India). The reverse carries the legend, FOR / LONG SERVICE / AND / GOOD CONDUCT.
1920-1930
King George V - type 2
In 1920 the swivelling scroll suspender was replaced by a fixed suspender.
In 1930 the name of the medal was changed to the Long Service and Good Conduct Military Medal.
Ribbon:
Originally dark crimson, this was amended to dark crimson with white edges for awards made from 1917 onwards.
Naming:
A combination of engraved and impressed.
Clasps:
No clasps were awarded for this medal.
Other
A Long Service medal was also issued to members of the Volunteer Force. This was a different design and had a green ribbon.
Image:
I've borrowed the photograph on this page from the Frontier Medals website. It shows a type 2 Army LSGC medal.