This is an Military Long Service Decoration, originally instituted in AD 1825 to honour long-standing service rendered by military officers and civil servants.
The decoration takes the form of a cross pattée with arms that broaden towards the extremities, each arm bordered by three raised fillet lines along its edges. At the centre of the medallion lies a royal crown, enclosed by a raised double-ring border. The centre of the reverse is inscribed with the Roman numerals ‘XXV’ or ‘XV’, denoting the recipient’s qualifying years of service. Suspended from a cornflower blue ribbon, its presentation closely resembles that of the Order of the Crown.
At the time of its initial institution, officers completing 25 years of service were awarded the cross, whilst non-commissioned officers and enlisted men serving for 21, 15, and 9 years received rectangular clasps in gilt, silver, and iron respectively. Following the reorganization in AD 1913, personnel serving for 25 and 15 years were awarded crosses in gilt and brass, whilst those completing 12 and 9 years of service received circular medals in silver or bronze. A decoration of comparable character existed in the form of the Landwehr Long Service Award. Most constituent states of the German Empire instituted their own long service decorations with varying regulations; amongst these, the cross of the Grand Duchy of Hesse was nearly identical in design to that of the Kingdom of Prussia, distinguishable solely by its red-and-white striped ribbon.
Barac, Borna. Reference Catalogue Orders Medals and Decorations of the World : instituted until 1945 : Part II Bronze Book D-G. Zagreb: OBOL d.o.o., 2010.
Hüsken, André. Katalog der Orden und Ehrenzeichen des Deutschen Reiches 1871–1945. Hamburg, Galerie d’Histoire André Hüsken, 1999.
Nimmergut, Jörg. Deutschland-Katalog: Orden & Ehrenzeichen von 1800–1945. 15. Aufl. (Ausgabe 2005/2006), München, Zentralstelle für wissenschaftliche Ordenskunde, 2005.