what is the {start time} for {Cluj-Napoca} has {country} as {Principality of Transylvania} ?
When did Cluj-Napoca change to the Principality of Transylvania?
When did the country Cluj-Napoca become the Principality of Transylvania?
SELECT ?r WHERE { ?q property:country resource:Principality_of_Transylvania . ?q property:start_time ?r . resource:Cluj-Napoca property:country ?q }
select distinct ?value  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q100188> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P17> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> <http://wikidata.dbpedia.org/resource/Q655621> .
?statement <http://www.wikidata.org/entity/P580> ?value. 
} 

SELECT ?value WHERE { wd:Q100188 p:P17 ?s . ?s ps:P17 wd:Q655621 . ?s pq:P580 ?value}