How many {conflict} are to/by {Crusades} ?
What is the number of Crusade conflicts?
How many Crusade conflicts were there?
SELECT ( COUNT ( ?b ) AS ?z ) { ?b property:conflict resource:Crusades }
SELECT (COUNT(?sub) AS ?subs ) {
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#subject> ?sub .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#predicate> <http://www.wikidata.org/entity/P607> .
?statement <http://www.w3.org/1999/02/22-rdf-syntax-ns#object> http://wikidata.dbpedia.org/resource/Q12546 .
} 

SELECT (COUNT(?sub) AS ?value ) { ?sub wdt:P607 wd:Q12546 }
10