query: SELECT DISTINCT ?item ?itemLabel ?battleLabel (YEAR(?time) AS ?year) WHERE {
    ?item wdt:P31/wdt:P279* wd:Q294440 ;
          wdt:P131 ?arrondissement ;
          wdt:P138 ?battle .
    ?arrondissement wdt:P131 wd:Q90 .
    ?battle wdt:P31 wd:Q178561 .
    OPTIONAL { ?battle wdt:P585|wdt:P580 ?time }
    SERVICE wikibase:label { bd:serviceParam wikibase:language "fr" . }
  } ORDER BY ?year ?battleLabel