Question: What is the key event of the sovereign state of Câlnic?
Paraphrase: What is the key occasion of the majestic state of Câlnic?
SPARQL (Wikidata): SELECT ?answer WHERE { wd:Q510532 wdt:P17 ?X . ?X wdt:P793 ?answer}
Answer: Russo-Turkish War of 1877–78, Romanian Revolution, Treaty of Berlin of 1878, Union of Transylvania with Romania, Unification of Wallachia and Moldavia