what is the {start time} for {George II of Great Britain} has {position held} as {duke} ?
When did George II of Great Britain become a duke?
When was George II of Great Britain became duke?
SELECT ?i WHERE { ?l property:start_time ?i . ?l property:position_held resource:duke . resource:George_II_of_Great_Britain property:position_held ?l }
select distinct ?value  where {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> <http://wikidata.dbpedia.org/resource/Q131981> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P39> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> <http://wikidata.dbpedia.org/resource/Q166886> .
?statement <http://www.wikidata.org/entity/P580> ?value. 
} 

SELECT ?value WHERE { wd:Q131981 p:P39 ?s . ?s ps:P39 wd:Q166886 . ?s pq:P580 ?value}