Commune of Haute-Marne (52700) of 100 inhabitants.
Semilly has undergone several administrative changes during its history. On August 1, 1972, it merged with the neighboring commune of Saint-Blin to form the new entity of Saint-Blin-Semilly. This union lasted until January 1, 1997, when the two communes regained their administrative autonomy.
Coordonnées 48° 15′ 35″ nord, 5° 27′ 33″ est Superficie 14,6 km2