Question: In what historical country was the official language of Latin used?
Paraphrase: In what chronicled nation was the official dialect of Latin used?
SPARQL (Wikidata):  select distinct ?sbj where { ?sbj wdt:P37 wd:Q397 . ?sbj wdt:P31 wd:Q3024240 } 
Answer: Kingdom of Mercia, East Francia, Electorate of Saxony, Duchy of Parma, Papal States, Polish–Lithuanian Commonwealth, Kingdom of Germany, Kingdom of León, Kingdom of Sicily, Kingdom of Aragon, Roman Kingdom, Crown of Aragon, Republic of Ragusa, Kingdom of Scotland, Kingdom of Asturias, Kingdom of Hungary, Gallic Empire, Armenian Kingdom of Cilicia, Duchy of Savoy, Middle Francia, Kingdom of Poland, Ostrogothic Kingdom, Principality of Transylvania, Duchy of Teschen, Golden Ambrosian Republic, Kingdom of Brittany, Kingdom of the Lombards, Kingdom of Croatia, Palmyrene Empire, Livonian confederation, Domain of Soissons, Principality of Capua, Republic of Pisa, Croatia in personal union with Hungary, Duchy of Masovia, Duchy of Croatia, Kingdom of Italy, Signoria of Milan, Roman Empire, Republic of Venice, Byzantine Empire, Holy Roman Empire, Western Roman Empire (395-476 AD), West Francia, Grand Duchy of Lithuania, Kingdom of Jerusalem