Instituted in 1845 and first awarded in 1847, with an annuity, to reward specially selected long service NCOs, eligibility for the award was extended in 1916 to WOs, NCOs and Men but without entitlement to an annuity. This unique work of reference not only lists the recipients of immediate awards between 1916 and 1928, some 27,550, but it also analyses the comparative rarity and therefore collectability of any medal, which depends to a large extent on the numbers issued to a particular unit or theatre of operations. Among nearly twenty appendices is a comprehensive analysis of awards to Corps and regiments by theatre. A résumé provides the reader with the changing history of the award, and some 1,200 footnotes include citations both for gallantry and valuable service, and point out highlights of MSM groups seen and identified. A remarkable piece of research.