Convention.

http://data.archives-nationales.culture.gouv.fr/instantiation/041781-c1p6xgz0kg97-1o2gu838j2whs-i1 an entity of type: Instantiation

Convention. 
xsd:date 1751-04-28 
28 avril 1751 
MC/ET/XXVIII/321 
Convention. 

data from the linked data cloud