diff --git a/data/ontologies/digital-heraldry-ontology-objects.ttl b/data/ontologies/digital-heraldry-ontology-objects.ttl
index 0300d62861098eec791ac602343f0e6bd81a2e66..21e32bf5bfa7fea1b0846d5391743b1acde386a6 100644
--- a/data/ontologies/digital-heraldry-ontology-objects.ttl
+++ b/data/ontologies/digital-heraldry-ontology-objects.ttl
@@ -54,8 +54,7 @@ vann:preferredNamespacePrefix rdf:type owl:AnnotationProperty .
 #################################################################
 
 ###  http://digitalheraldry.org/digital-heraldry-ontology/objects#datedInCentury
-dhoo:datedInCentury rdf:type owl:ObjectProperty ;
-                    rdfs:subPropertyOf owl:topObjectProperty .
+dhoo:datedInCentury rdf:type owl:ObjectProperty .
 
 
 ###  http://digitalheraldry.org/digital-heraldry-ontology/objects#hasDate
@@ -68,6 +67,10 @@ dhoo:hasEarliestDate rdf:type owl:ObjectProperty ;
                      rdfs:subPropertyOf dhoo:hasDate .
 
 
+###  http://digitalheraldry.org/digital-heraldry-ontology/objects#hasGridSystem
+dhoo:hasGridSystem rdf:type owl:ObjectProperty .
+
+
 ###  http://digitalheraldry.org/digital-heraldry-ontology/objects#hasLatestDate
 dhoo:hasLatestDate rdf:type owl:ObjectProperty ;
                    rdfs:subPropertyOf dhoo:hasDate .
diff --git a/data/rdf-output/research-dataset/digital-heraldry-knowledge-graph-research-dataset.jsonld b/data/rdf-output/research-dataset/digital-heraldry-knowledge-graph-research-dataset.jsonld
index 97876717dae263986cc5b3011e0d8f63552cc346..110ac0d7ebfcf8cf35d68533d83b7dc637cd90e7 100644
Binary files a/data/rdf-output/research-dataset/digital-heraldry-knowledge-graph-research-dataset.jsonld and b/data/rdf-output/research-dataset/digital-heraldry-knowledge-graph-research-dataset.jsonld differ
diff --git a/data/rdf-output/research-dataset/digital-heraldry-knowledge-graph-research-dataset.ttl b/data/rdf-output/research-dataset/digital-heraldry-knowledge-graph-research-dataset.ttl
index 43aa8f5f6c9f591d632e6c0b8ad000cdfa78332f..7199a701029cf8a7689f2f0af1ec1a88315e9054 100644
Binary files a/data/rdf-output/research-dataset/digital-heraldry-knowledge-graph-research-dataset.ttl and b/data/rdf-output/research-dataset/digital-heraldry-knowledge-graph-research-dataset.ttl differ
diff --git a/src/rdf-mappings/integrate_manuscript_metadata_into_kg.py b/src/rdf-mappings/integrate_manuscript_metadata_into_kg.py
index e6b7abd176b448b19ad184a2c643e905b2b36089..16fe91f864ac209f42c35a21afa84aba9384f422 100644
--- a/src/rdf-mappings/integrate_manuscript_metadata_into_kg.py
+++ b/src/rdf-mappings/integrate_manuscript_metadata_into_kg.py
@@ -88,6 +88,9 @@ if __name__ == '__main__':
 
             if not pd.isnull(row['library-place']):
                 g.add((manuscript_uri, dho_obj_n.hasLibraryPlace, Literal(row['library-place'], datatype=XSD.string)))
+            
+            if not pd.isnull(row['grid-system']):
+                g.add((manuscript_uri, dho_obj_n.hasGridSystem, Literal(row['grid-system'], datatype=XSD.string)))
 
     # Integrate knowledge graph on heraldic data
     print('Loading Knowledge Graph file...')