Question: When did Mainz cease to be a part of the Kingdom of Persia?
Paraphrase: From which year did Mainz ceased to be a part of the Kingdom of Persia?
SPARQL (Wikidata): SELECT ?value WHERE { wd:Q1720 p:P17 ?s . ?s ps:P17 wd:Q27306 . ?s pq:P582 ?value}